California’s State Soil

We all know California has many state symbols. The grizzly bear flying in the state flag, golden poppies and the valley quail are all symbols that connect you back to our golden state. Did you know that California has a state soil?

What is a State Soil?

A state soil is a soil that has special significance to a particular state. Each state in the United States has selected a state soil, twenty of which have been legislatively established. These “Official State Soils” share the same level of distinction as official state flowers and birds. Also, representative soils have been selected for Puerto Rico and the Virgin Islands. California’s State Soil is the “San Joaquin” soil. The San Joaquin soil was initially documented and officially established in California in 1900 and therefore is the oldest, continuously recognized soil series within the state. It was designated the official state soil of California in 1997.

San Joaquin soil has a distinctive soil horizon (layer) known as a “hardpan” to many people. It is extremely hard and it can be chipped with mechanical means or through use of a pick or very strong, heavy shovel. Typically, San Joaquin soils have a brown to reddish brown surface with a loam texture that has an accumulation of organic matter. It was chosen as the California State Soil because of its interesting soil characteristics, had agricultural significance, had extensive distribution, had a soil name recognizably Californian, and had its typical location in California. California’s central valley has more than half a million acres of San Joaquin soils that can be found along the east side of the San Joaquin and lower Sacramento Valleys as a small but important part of this huge California agricultural base.

A little about soil profiles and textures

Soil Horizons: Soil is made up of distinct layers, called horizons. Each layer has its own characteristics that make it different from all of the other layers. These characteristics play a very important role in what the soil is used for and why it is important.

O HORIZON- This is the top layer of soil that is made up of living and decomposed materials like leaves, plants, and bugs. This layer is very thin and is usually pretty dark.

A HORIZON- This is the layer that we call “topsoil” and it is located just below the O Horizon. This layer is made up of minerals and decomposed organic matter and it is also very dark in color. This is the layer that many plants roots grow in.

B HORIZON- This is the layer that we call “subsoil” and it is located just below the A Horizon. This layer has clay and mineral deposits and less organic materials than the layers above it. This layer is also lighter in color than the layers above it.

C HORIZON- This is the layer that we call “regolith” and it is located just below the B Horizon. This layer is made up of slightly unbroken rock and only a little bit of organic material is found here. Plant roots are not found in this layer.

Soil Textures: Three types of particles are found in soil: sand, silt and clay. Soil texture is classified by the type of particle that makes up the majority of the soil. Each soil type has a distinctive textural feel and holding a sample of your garden soil in your hand may help you determine the type of texture that makes up your garden soil.

Sandy Soil: Sand is the largest of the particles found in soil. It is a sharp-edged material, giving the soil a gritty feel. When wet, it remains course and breaks apart easily. Beach sand is at the extreme end of sandy soils. Sandy soil holds almost no nutrients and does not retain moisture. Plants do not grow well in this type of soil.

Silty Soil:  Silt particles are smooth and smaller than sand particles. When wet, a silty soil feels mud-like; it’s smooth and has a silky texture. It’s rich in nutrients but retains moisture to the point where garden plants are unable to access oxygen. In a silty soil, plants wilt because they can’t breathe.

Clay Soil: Clay is the smallest of the particles and a clay soil will clump and feel sticky when wet. Air flow between particles is limited if not non-existent. When dry, the soil has a dusty feel to it and the surface is hard and dense, making it difficult to work the soil for tilling or digging. Although high in nutrients, clay soil is less than ideal for gardens. Plant roots may not be able to penetrate the dense soils to access nutrients and oxygen.

Loamy Soil: Loam is a combination of all three particles– sand, silt and clay–in nearly-equal proportions. The large sand particles promote drainage and air flow within the soil. The smaller silt particles are rich in nutrients and aid in moisture retention. Clay, also rich in nutrients, balances the poor soil retention of the sand and the excessive moisture of the silt.

Does your garden have the official state soil? Find out the name of the soil in your landscape by visiting the NRCS’s web soil survey page,

If you would like to see all of California’s state symbols from fish to gemstone, visit

For gardening related questions, call the UC Master Gardener office at 209-953-6112, or visit our website:


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An up-close look at pollen (achoo!) By Kathy Ikeda

For many people, pollen is the “p-word”. . . as in, “PLEASE, don’t say that word!” The mere mention of pollen can conjure up runny noses, watery and itchy eyes, and looks of desperation from those with hay fever. Here in the fertile, crop-rich San Joaquin Valley, it’s often said that if you don’t already have allergies, you’ll develop them.

Trees such as oaks, birches, conifers (pines, firs, spruces), and nut crops (walnuts, almonds, pecans) are especially prolific producers of pollen, and they’re ubiquitous in our area. They’re joined by other common pollen-producing plants, including grasses and many of our favorite garden flowers. It’s an allergy sufferer’s nightmare.

Pollen literally means “fine flour” or “mill dust” in Latin. While it’s a health nuisance, it’s also a valuable and necessary evil.

We’re familiar with pollen as that yellowish, powdery-looking stuff that drifts away from trees and other plants in spring and summer, making us miserable as it floats through the air, collects on our cars and homes, and settles in our nostrils. But without pollen, we literally couldn’t survive. The vast majority of plants on Earth depend on pollen for their reproduction, and we in turn depend on plants for food and oxygen.

Pollen is unique to seed-producing plants, which are divided into the flowering plants (Angiosperms) and the cone-bearing plants (Gymnosperms). The pollen-bearing structures of these plants are contained either in the flowers or the cones. More primitive plants such as ferns, fungi, mosses, and horsetails don’t make pollen; instead, they produce spores.

So, what exactly is pollen, anyway?

A clue to pollen’s specific purpose lies in the aforementioned scientific classifications of pollen-producing plants: the suffix –sperm means “seed” in Greek. Pollen is the male vehicle for a seed-forming plant’s sexual reproduction. Each microscopic pollen grain has a hard outer coating that protects the inner contents—two sperm cells and a tube cell—from damage and dehydration.

Plants fall into two categories when it comes to the type of pollination: (1) self-pollinated, or (2) cross-pollinated, where pollen from one plant must transfer to another plant of the same species.

Pollination begins when grains of pollen move from the male part of a plant to the female part of a plant. Pollen transfer can occur in one of two ways: (1) abiotic pollination, where pollen is carried by wind or water (most common in grasses and trees), or (2) the far-more-typical biotic pollination, where a living organism such as a bee, butterfly, moth, wasp, fly, bird, bat, or other animal moves the pollen (most common in non-tree flowering plants).

Once a pollen grain comes in contact with the female part of a plant, it germinates. A pollen tube develops, emerging through a specialized opening in the outer covering then extending toward the structure that holds the egg. The sperm cells then leave the pollen grain and travel through the pollen tube, ending their journey when they reach the egg. Fertilization occurs once the plant’s egg/ovule and sperm cells unite, and that initiates seed development.

Some amazing pollen-related facts about corn: Just one stalk can produce about 18 million pollen grains! The pollen grains land on the ends of the female corn silk; there is one strand of silk attached to each developing kernel. The single-celled pollen tubes that grow from the pollen grains through the silk can be up to a foot long!

Many small members of the animal kingdom depend upon pollen. Honeybees and native bees use protein-rich pollen, either eating it themselves or mixing it with sugary nectar before feeding it to their developing larvae. (Pollen is not used to make honey; honey is regurgitated nectar.) Some beetles—including ladybugs—and many common types of web-weaving spiders also consume pollen as part of their diet.

When seen under a microscope, pollen grains are exquisitely beautiful natural works of art. Their outer coatings are intricately patterned, spiked, or pitted, and different plant species produce their own unique pollen designs. Pollen can be sticky-surfaced or spine-studded so that it’s easily carried on the hair, feathers, or fur of pollinators, or it can be lightweight and aerodynamically crafted to float in a breeze.

False-color scanning electron microscope image of pollen grains from a variety of common plants: sunflower, morning glory, prairie hollyhock, oriental lily, evening primrose and castor bean. (Public domain image from the Dartmouth Electron Microscope Facility)

For more information and a visual treat, read the book Pollen: The Hidden Sexuality of Flowers, or search the Internet for “pollen electron microscopy” to see extraordinary images. And try very hard to appreciate pollen, even as it makes you sneeze.

For gardening related questions, call the UC Master Gardener office at 209-953-6112, or use our website:


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Deadheading: what it is and why it’s important

What is deadheading? The word sounds somewhat sinister, and if you belong to a certain generation, you might associate the term with those avid fans of a certain 1970s rock band. (Followers of the group The Grateful Dead are known as “Deadheads.”) While the word might lead to amusing confusion, a gardener’s use of the term deadheading has nothing to do with either music or macabre rites.

In the gardening world, deadheading is the practice of removing withered and faded blooms from a plant. There are several reasons why you should make this chore a standard part of garden upkeep.

One of the best reasons to deadhead plants is to improve their appearance. Brown, dry flowers covering a plant tend to look unattractive, and removing them on a regular schedule can tidy up and brighten most landscapes.

Another important reason to deadhead plants is to extend their blooming season and/or to increase the number of flowers they produce in a given year. It all comes down to science. The main purpose of flowers is to attract pollinators, and once that purpose has been served, the pretty blooms’ jobs are done. The plant then diverts its energy into the developing seed heads or seedpods, because seeds are what ensure its ongoing survival. However, if those young seeds are removed, the plant once again channels its energy into the first stage of reproduction. The result: more flowers!

Most annual plants and many perennial plants will continue to bloom (or have a second period of bloom) if deadheaded on a regular basis. Common bedding plants such as marigolds, pansies, and snapdragons benefit from deadheading, as do many favorite perennials, including blanket flowers, coneflowers, cosmos, dahlias, lupines, Shasta daisies, yarrow, and more.

Deadheading is also wise if you have plants that self-sow easily. The word sow means “to plant seed by scattering it on the earth,” and that’s precisely what these types of plants do. Each plant can produce hundreds to thousands of easily germinating seeds, and when the seedpods ripen and dry, they distribute the seeds over a wide area, either by popping open suddenly or with help form the wind. To control the spread of these plants—including beautiful and prolific ones such as California poppies—deadheading throughout the blooming season is recommended to prevent massive re-sprouting the following spring.

Some flowering plants don’t need to be deadheaded, because their flowers drop off on their own once spent. This process, whereby a plant discards a part no longer needed, is called abscission. Plants with flowers that naturally abscise are camellias, impatiens, and rosemary. Other ornamental plants such as fuchsias don’t produce a lot of seeds, and don’t require deadheading.

It’s very easy to deadhead. As a flower fades or drops its petals, snip off its stem just above the first complete set of healthy leaves. On plants with delicate or tender flower stems, this technique can be done without any garden tools; just pinch the stem between your thumb and forefinger. In other instances, where the plants have tough or sturdy stems—especially roses—use a clean pair of bypass pruners with sharp blades to make clean cuts. For plants with a profusion of small flowers, an occasional light shearing is the easiest way to deadhead, but try to avoid cutting off any developing flower buds still left on the plant. Any disease-free trimmings can be composted.

Avoid deadheading when growing plants with decorative seedheads or fruits (such as buckwheats) and plants with seeds that attract birds (such as black-eyed Susan, coreopsis, and sunflowers). Allow these plants to progress through their flowering cycle naturally, and enjoy the transformation from bloom to a different show. Or, if you want to collect and grow plants from seed next year, allow some of the last flowers of the season to reach maturity.

The job of deadheading can seem overwhelming if left undone for weeks at a time. Not many gardeners want to spend valuable time on such a tedious task, snipping dead flowers for hours on end! But if you devote a few minutes every day or two wandering your yard and picking off spent blooms here and there, the seemingly daunting task can become a pleasure. What better way to become intimately familiar with your garden, enjoy some fresh air and natural beauty on a daily basis, and get a healthy dose of vitamin D with a little time in the sunlight? Both you and your garden will benefit.

For gardening-related questions, call the UC Master Gardener office at 209-953-6112, or use our website.


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How to Achieve a Healthy Lawn

Nothing complements a neat house and a well-kept yard like a green, lush lawn. A properly managed lawn will stay green and attractive much of the year, minimize environmental impact and consume fewer resources. Properly cared for lawns can outcompete weeds and other pests requiring little or no applications of chemical pesticides. By taking a few easy steps, you can end up with the greenest, healthiest lawn on your block.

Irrigation is the most important component of lawn maintenance. In order for a lawn to thrive, it must have a strong, vigorous root system. In general, your lawn needs water when the top two inches of soil have dried out. If footprints remain visible after walking on the lawn or if the grass has changed color or has started to wilt, it’s time to water.

The best times to water are between 2 and 8 in the morning. At these times, water use is most efficient, water loss from evaporation is minimal, and distribution is usually good because of good water pressure and limited wind. During the afternoon, water is wasted due to high evaporation rates. Do not water during the evening or pre-midnight hours because grass blades are susceptible to diseases if they are wet during cool nights. Deeper, less frequent watering is best for most lawns. Make sure your sprinkler system does not produce runoff, especially on slopes. If you see runoff, use shorter watering times and repeat the cycle to allow time for the water to move into the soil.

Periodically, you should go out and manually turn your sprinklers on to check for leaks, broken or misdirected heads, faulty valves, and other malfunctions and make sure you are not watering the driveway, sidewalks, and streets.


You might not think there is much to mowing your lawn but proper mowing is critical for attractive, well-groomed lawns.

One of the biggest mistakes people make is mowing too short. Optimum cutting height is determined by the growth habit of a particular grass and its leaf texture. Mowing too low removes too much of the grass’s food producing area. As the grass literally starves, the lawn thins and looks poor. Conversely, mowing too high can hurt the appearance or usefulness of the turfed area.

No single mowing height is best for all turfgrasses; mowers must be set differently for each grass. Within its optimum mowing height range, each grass species will be healthier and have a deeper root system the higher the grass is mowed. Also, a grass that is cut higher is more tolerant of drought, heat, traffic, shade, disease, and pests than one that is cut lower.

As a general guide, follow the one-third rule: mow often enough so that no more than one-third of the length of the grass blades is removed at any one time. Do not drastically or suddenly change the cutting height. If the grass has become too tall, re-establish the recommended height by mowing more frequently for a while and gradually lowering the mowing height of successive cuttings, following the one-third rule.

Grass blades cut best when they are dry, wet grass sticks to mower blades and clogs the mower. When you are our mowing, try to change the direction of mowing periodically to prevent a “washboard” effect. You should sharpen lawnmower blades regularly for a clean cut. Dull mowers leave a ragged appearance from crushed or uncut grass blades and damaged grass may be more susceptible to disease.  Since mowing stresses the grass, do not mow a lawn under drought or other climatic stress conditions. Grass that is suffering from lack of water should be watered and allowed to dry before being mowed.

Grass clippings make up a large portion of California’s solid waste stream during the growing season. With few exceptions, it is actually best to leave the clippings on the lawn after mowing. This practice is called grasscycling. Grass clippings decompose quickly and release valuable nutrients back into the soil, supplying about 20% of the fertilizer requirements of most grasses.

Creating a fertilizer program that is right for your lawn involves many factors. Turfgrass species, type of fertilizer, climate, soil, desired quality level, and budgetary considerations all play a role.

A good nutrient supply is important for a healthy, vigorously growing lawn. Lawns that are discolored, slow growing, or have weeds or other pest problems might not be properly fertilized. Lawn fertilizers usually supply three main nutrients: nitrogen, phosphorus, and potassium. However, nitrogen is the only nutrient that turfgrass needs on a regular basis. Too much or improperly applied fertilizer can injure lawns and can contribute to water pollution through runoff.

You should first identify the type of grass you have and select the proper fertilizer rate and application timing. A few days before you fertilize, deeply irrigate your lawn so that the soil is moist; the grass blades should be dry by the time you start your application. After fertilizing, irrigate just enough to wash the fertilizer off the leaves and into the soil.

Make sure you pour the material into your spreader over a driveway or other cement area where spilled material can be swept up (pouring over a lawn where spilling may occur can lead to burn); do not let excess fertilizer be washed into storm drains.

Our Master Gardeners are eager to answer you lawn questions and have more information to help you figure out turf species, the proper time to fertilize and can help with irrigation scheduling.  You can contact the UC Master Gardeners at 209-953-6112. More information can also be found on our website,

Information for this article was taken from the UC Guide to Healthy Lawns website.


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Spring Garden Chores – It’s Time to Thin Fruit

Spring is a busy time in the garden and gardeners often find themselves with a list chores to complete. By now, spring fever shopping at the local nursery has lead to a car full of plants that still need a home in your yard, the weeds are abundant, the battle with the aphids is beginning and we can’t forget the planning and planting of summer vegetable gardens. Your fruit tree should be loaded with small fruit and I bet you can already taste that ripe, juicy peach on a hot summer day.

One of the most often overlooked chores is fruit thinning. Fruit trees often set more fruit than they can support, especially if the trees were not properly pruned during the previous season. Excessive fruit compete with each other for carbohydrates (stored energy) and remain small.


Thinning immature fruit at the appropriate time allows each remaining fruit to develop to its maximum size. Less-crowded fruit receive more sunlight, so fruit color and flavor may be improved.

Reducing the fruit load through proper pruning and fruit thinning, especially near the ends of branches, lessens the chances of limb breakage. It’s much less tragic to pluck many tiny peaches off your favorite tree than to lose an entire limb because it was so heavily weighed down. It can also reduce alternate bearing (a cycle in which the tree bears excessively in one year and little the next year).

Fruit thinning can also reduce the spread of some diseases. For example, if the fruit are touching each other, brown rot can quickly spread from one fruit to another just before harvest.


Flowers and fruits naturally thin themselves, often at distinct time periods. Blossoms that were not pollinated turn yellow and drop off just after flowering. Small, immature fruits often drop naturally during what is known as “June drop,” which usually occurs in May in California. Fruits that are diseased or infested with insects may also drop prematurely.


Cherries, figs, persimmons, pomegranates, citrus, and nut trees do not usually require thinning. However, branches of persimmon trees can break from the weight of a heavy crop and may benefit from some fruit thinning or branch propping. All stone fruits (peaches, apricots, nectarines, cherries, plums, etc.) require thinning. Pome fruits like apples and Asian pears as well as most European pears require thinning. Bartlett pears often thin themselves, and harvesting larger fruit early (early to mid-July) allows the smaller fruit to increase in size for a second pick 1 to 2 weeks later.


Fruit should be thinned when they are fairly small–typically from early April (for early-ripening fruit) to mid-May (for late-ripening fruit). The amount of fruit to thin depends on the species and the overall fruit load on the tree. For example, stone fruits such as apricots and plums are fairly small, so they should be thinned to 2 to 4 inches apart on the branch. Peaches and nectarines should be thinned to about 3 to 5 inches. When the crop is heavy, fruit should be spaced no less than 6 to 8 inches apart.

Unlike stone fruits, which produce one fruit per bud, pome fruits (apples and pears) produce a cluster of flowers and fruit from each bud. Thin to no more than one to two fruit per cluster, depending on the total fruit set and growing conditions


It’s a simple (but tedious) task to thin fruit and it doesn’t require any special equipment, all you need is your hands. To avoid damaging branches, twist fruit off gently rather than pulling it. Remove “doubles” (two fruit fused together) and small, disfigured, or damaged fruit when you have the option. Extremely small or damaged fruit should be removed regardless of spacing, and leaving the largest fruits on the tree is more important than exact spacing. So, you will have to use your own judgment when making decisions about which fruit to thin and which to leave.  Keep the largest fruit whenever possible.

If thinning by hand is impractical you can use a pole to help with the process. Pole-thinning is much faster, and although it is less accurate, the results are often sufficient. Attach a short rubber hose, cloth, or thick tape to the end of the pole to reduce scarring or bruising of branches. Strike individual fruit or clusters to remove a portion of the fruit. With experience, you will be able to strike a cluster once or twice with just enough force to adequately break up the cluster.

Once you have experienced the fruit at its best, thinning is performed with a solid sense of purpose and maybe even some excitement.


For gardening-related questions, call the UC Master Gardener office at 209-953-6112, or use our website:

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Joining the succulent parade.

Succulents and cacti are a new world-to me. The word “succulent” comes from the Latin word sucus, meaning juice, or sap and we are unlikely to be saps for liking these plants. Succulents have the ability to thrive on mist and dew, which makes them equipped to survive with scarce water sources. In our drought plagued California, gardeners are always looking for ways to conserve water and yet still enjoy gardening. So one way to do this is to get into the succulent and cacti craze. I have to admit that I have not joined in very well though I am interested in saving water. I have had Jade plants and Hens and Chicks (Echeveria) in my plant repertoire for about fifty years, but not too many other succulents.

So, I am writing this article as a novice in this area. Recently the University of California Master Gardener’s put on a Smart Gardening Conference at the Ag Center which was well attended and I

A collection of succulent starts in a beautiful cedar box---all compliments of the efforts of Master Gardeners at the Smart Gardening Conference in March.

particularly enjoyed the workshop on planting succulents. It was a power point presentation by several of our outstanding Master Gardeners who grow succulents followed by a hands-on planting of various succulent cuttings that were furnished by these gardeners and others. I took home my varieties of succulents in a cute little cedar planter box that was also put together for class attendees by a Master Gardener and her husband. I must say that the volunteer effort these Master Gardeners give to the community is amazing.

Here are some learning points I took away with me. All cacti are succulents, but not all succulents are cacti. Succulents are plants that store water in their leaves, stems or roots. Succulents have evolved in a variety of environments and plant groups. Over 25 plant families have multiple succulents found within them. There are hundreds if not thousands of species of succulents in the world; a pretty large number to attempt to grow in a lifetime of gardening. Succulents grow well in California because of the similarity of climates to those where succulents have evolved.

A Sempervivum succulent of unknown species that I have had for many years.

Some succulents can be grown in soil outdoors and some in containers either indoors or outdoors. If grown in containers some things to consider are: the ultimate size and shape. Hence, small plant should go in small pots and shallow pots are good for most succulents. Good drainage is essential and be prepared to repot when they outgrow the container. A variety of containers can be artfully employed so use your imagination. Succulents can be killed with poor drainage and overwatering. If you have clay soils which don’t drain well then change the soil. Good soil for succulents contains almost equal parts of gravel, coarse sand and topsoil, with a healthy dose of good compost worked into a depth of 5-6 inches.

Water succulents only when soil is dry and they need less water when they are dormant. Some go dormant in winter and some in summer so you need to know that. Generally, growth is in the spring and fall and then they need more water. Ceramic pots retain moisture longer than unglazed clay pots and don’t leave standing water in saucers under the container. Overwatering is easy to do, so if in doubt don’t water. Remember they are succulents and have water in reserve for drought.

Most succulents don’t like direct Valley sun all day, so partial shade or afternoon shade is good for some and others like shade. Most don’t like freezing weather and some should be sheltered if it gets below 40 degrees. Most problems with succulents occur because of overwatering or under watering, or too much sun exposure or too little or because of temperature that are too cold or too hot. Succulents can be grown as houseplants or taken indoors for the winter if not frost hardy. Succulent indoors need 6 hours of sunlight, but avoid sunburn by placing in an east facing window.

For more information on common succulents that are popular and that do well under varying conditions see: A good book on succulents is Succulents Simplified: Growing, Designing, and Crafting with 100 Easy-Care Varieties by Debra Lee Baldwin. She knows a lot about succulents. One of the joys of gardening is to keep on learning!

Speaking of learning, the San Joaquin County Master Gardeners are holding an Open Garden Day on Saturday April 14, from 9 AM until noon at the Robert J Cabral Ag Center at 2101 East Earhart Ave off of Arch Road. It will showcase the UCCE Learning Landscape, a demonstration garden created and maintained by the Master Gardeners. Come to learn more about pruning, composting, planting and seasonal garden chores and there will be summer vegetables for sale as well as UC publications (cash or check only). You can bring up to 2 tools for a free tune-up at the tool sharpening table. In case of rain, the event will be cancelled.

If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112. More information can be found on our website:

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Here comes the sun (and what gardeners should know about it)

As I pondered a topic for this article, brilliant rays of sunlight penetrated the dark rain clouds, bathing my garden with a beautiful rosy glow. What perfect and timely inspiration.

With respect to gardens, our sun is far more than a “mass of incandescent gas” (term borrowed from the song “Why Does the Sun Shine?”); the radiation from our nearby star literally powers the engine of plant growth. Sunlight is the fuel that allows plants to convert water and carbon dioxide gas into glucose—a type of sugar—and oxygen—a vital component of the air we breathe. It’s a miracle of nature.

Sunlight and plant health are closely intertwined, so here are some things to consider during your spring planting and gardening chores.

A nursery plant tag with sun exposure information at the bottom (Kathy Ikeda)

All plants can be categorized by the amount of sun exposure they prefer: full sun (6 hours or more a day), part sun/shade, or full shade (1 hour or less a day). These distinctions are a standard part of nursery plant tags and reputable gardening references such as the Sunset Western Garden Book, for good reason. One of the most important factors for a plant’s health is sun exposure.

If a sun-loving plant is planted in an area with too much shade, it won’t get the light it needs for optimal health and growth. Conversely, a shade-loving plant will be severely stressed or killed if planted in an area where it receives too much sun.

Not all sunlight is created equal. Morning sunlight is less intense than the hot afternoon sun, particularly during our scorching summers. A plant that receives two hours of full sun early in the day lives in a far different and milder microclimate than a plant that gets full sun between 3:00 and 5:00 p.m. Sunlight is essential for plant’s survival, but there can be too much of a good thing.

The angle of the sun and the length of day changes constantly throughout the year, so a spot in the garden that might be shady in the winter could get full afternoon sun for many hours in the summertime. This can have serious consequences for plant health. Make sure you understand the year-round conditions—including seasonal sun exposure—of any planting site, and then choose the plants for that location appropriately.

Heat and light are two distinct components of sunlight, and too little or too much of either can harm plants. Symptoms of inadequate sunlight include weak, spindly growth and pale leaves. Some types of damage caused by excessive sun include bud drop, leaf scorch, leaf tip burn, sunburn, sunscald, and wilting. Sunscald is one of the most serious injuries; with too much sun exposure, the bark splits, cracks, and peels away to expose the living plant tissue underneath, which then becomes susceptible to diseases, insect damage, and death.

Outdoor plants aren’t the only ones affected by sun exposure; houseplants are too. If they’re placed in a dark corner, they will start to appear sickly, and might develop long, straggly growth toward a nearby window. On the other hand, plants placed near a south- or west-facing window might sustain damage from too much heat or direct sunlight exposure in the late spring and summer.

Sunscald damage on a large Japanese maple branch (Kathy Ikeda)

The sun is also is factor in pruning. If you open up the structure of a tree or shrub by removing branches, the trunk and remaining branches or stems might suddenly be exposed to strong sunlight since they’re no longer shaded by foliage. Monitor the plant to see where the sun hits newly-exposed wood, then prevent sunscald by painting those surfaces with a protective solution made by mixing equal parts water and white, water-based, flat, interior latex paint. Paint only the parts exposed to strong sunlight—upper and southwest-facing surfaces—not those that are shaded. (Do not use “sealing compounds” or tar on branches or pruning cuts; they do more harm than good. Simply prune on a dry day and allow the cut surface to heal naturally.)

Keep the sun in mind when planning a vegetable garden or home orchard. Vegetables need at least 8 hours of sunlight per day for optimal growth and crop production. Fruit, nut, and citrus trees need 6 to 8 or more hours of sunlight a day in order to be at their healthiest and most productive, and heat is the most important factor in the ripening of citrus fruit.

Some cautionary notes about citrus: the bark of lemon trees is especially susceptible to sunburn, as are the fruits and leaves of Red Ruby grapefruit. Newly planted citrus trees appreciate some sun protection; loosely wrap their trunks with newspaper, or use the diluted paint mixture described above to coat the trunk and exposed branches.

Sun exposure should also influence your choice of garden mulch. Inorganic mulches such as stone and gravel can be appropriate in shady locations or when placed around heat-loving plants. However, rock retains far more heat than organic mulches such as bark. Under full summer sun, rock mulch absorbs heat during the day and radiates it throughout the night; this can literally bake plants, scorching their leaves, damaging their bark, and cooking their surface roots.

May sunshine brighten your days, and may you learn how to manage it in your garden!

For gardening-related questions, call the UC Master Gardener office at 209-953-6112, or use our website.

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Keeping Your Pet Safe in The Garden

With spring just around the corner comes an increase in outdoor activities, one of those being gardening. You may be spending your day dreaming of plant combinations you

Cyclamen are toxic to pets

can use to enhance your landscape. However, besides beauty and functionality, we have to think about our four-legged family members who search for adventure in our lawns and gardens. There are some important things to consider when landscaping if you have pets.

Choose your plants wisely. Toxicity levels vary in different plants and cause different reactions that can be mild to quite serious (even deadly). Before you shop for plants, check the ASPCA Toxic and Non-Toxic Plants website. Also, avoid planting thorny and spiny plants, which can cause serious eye injuries. In addition, beware of wild mushrooms in your yard. Many wild mushrooms produce aflatoxins, which can be fatal if ingested by dogs; if mushrooms appear, dig and dispose of them immediately.

Here are a few common plants that are poisonous to animals.

Daffodil-These flowers contain a chemical compound that triggers vomiting. Ingestion of the bulb or any part of the plant can cause, in addition to vomiting, diarrhea, abdominal pain, heart rhythm abnormalities and respiratory depression.

Tulip and Hyacinth – Compounds in tulips and hyacinths can cause profuse drooling, vomiting and diarrhea — leading to dehydration and additional problems.  All parts of the plant are toxic, but the lactones and alkaloids are concentrated in the bulbs, so make sure that your dog isn’t digging up the bulbs!

Lily -Some lilies (Peace, Peruvian and Calla) contain oxalate crystals that cause minor signs of toxicity, and true lilies (Tiger, Day, Asiatic, Easter and Japanese Show lilies) can be fatal. Cats are especially sensitive to lily poisoning, so be very careful to keep your cats away from lilies of any kind, including the Amaryllis, Easter lilies and Stargazer lilies popular around holidays.

Lily of the Valley -These plants contain sugars that affect how the cardiac muscle contracts. Ingesting any part of the plant can cause vomiting, diarrhea, decreased heart rate, heart rhythm abnormalities and possibly seizures.

Crocus –Both the spring and fall blooming varieties are toxic. These plants can cause vomiting and diarrhea when ingested.

Chrysanthemum (including Daisies) – The chemical compounds lactones and pyrethrins as well as other potential irritants in the plant can cause irritation to the gastrointestinal tract and affect the nervous system. Signs of toxicity include vomiting, diarrhea, increased salivation and incoordination.

Many lilies are toxic to pets

Cyclamen -The tubers or rhizomes contain the toxic glycoside cyclanin, which can destroy red blood cells. Ingestion can cause salivation, vomiting, diarrhea, refusal to eat, seizures and heart rhythm abnormalities.

Rhododendron -Resins bind to and modify sodium channels, which allows calcium movement into cells and can lead to vomiting, diarrhea, abdominal pain and refusal to

eat. The leaves are the most toxic, but all parts of the plant, including trimmings, are toxic.

Cycad (such as Sago palm) – Sago palm is a member of the cycad family.  All cycads are mildly to very toxic so should not be ingested by pets or children.  The toxic compounds cause vomiting and liver toxicity.

Other Things to Consider


Mulch has many beneficial properties, such as moisture retention, weed suppression, and beautification. However, certain mulches can cause reactions in your animals. Cocoa bean mulch is particularly toxic to dogs and is best to be avoided in the garden. Rubber mulch claims to be chemical free, but plastic is far from a natural substance. Also, some wood mulches may contain color dyes to which your animals may be sensitive. Use natural wood mulches as a safer choice for your animals but always keep an eye on your pets around mulch, especially if they like to chew.


Most fertilizers only cause gastrointestinal irritation when consumed, but there are some products that are more toxic.

Blood meal: If ingested this can cause vomiting, diarrhea and severe inflammation of the pancreas due to its high nitrogen content. Some types are also fortified with iron, which can result in iron overload, which is toxic.

Bone meal: This is what makes fertilizer so desirable to dogs. When consumed in large amounts, this forms a large bowling ball of cement-like consistency in the stomach that can block the gastrointestinal tract and require surgery to remove.

Rose and plant fertilizers: Some of these contain organophosphates which can cause buildup of a neurotransmitter that overstimulates certain receptors and is highly toxic to dogs in very small amounts.

Be aware of toxic risks. Remember, many things that are not desirable to people are readily ingested by dogs and cats. Learn to identify problematic plants and symptoms of toxicity.

Reduce access to plants. Consider the ability of the animal to jump and dig when making sure toxic substances aren’t accessible. For example, placing a house plant on top of a bookshelf may not be sufficient if there are cats that like to jump up onto high shelves.  Covering fertilizer areas with mulch may not be sufficient because dogs can dig and find the fertilizer or bulbs buried beneath. Always err on the side of caution when determining which plants to bring into the house or plant in the yard!

If you suspect your pet has ingested any of the following plants, call your veterinarian immediately or the APCC 24-hour emergency poison hotline at 1-888-426-4435.

If you have a gardening related question, you can contact the UC Master Gardeners at 209-953-6112. More information can be found at:

Information for this article was taken from the UC Davis One Health Blog, 10 Garden Plants That Are Toxic to Pets.

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Composting—It is good for a more sustainable lifestyle and your garden by Lee Miller

Recently when I mentioned that I was collecting coffee grounds for compost, I was asked “What is compost?” I was a little shocked since being a gardener I thought everyone would know what compost is. Likely there are many people who don’t recognize the term, because they do not garden or, if they do, may find compost a foreign concept if they are hooked on using chemical fertilizers which are advertised widely. So what is compost?

Compost is essentially decomposed organic matter that can be made up from various organic components such as kitchen scraps, leaves, grass clippings, weeds, plants from the garden, including coffee grounds, alfalfa meal, hay, straw and even wood shavings and sawdust. The process of biodegrading and recycling these organic materials into useful compost is called composting. It provides a recycled product that organically improves the fertility, condition and water holding capacity of your soil. Besides the value to the soil, composting is a sustainability practice that keeps organic materials out of landfills and instead recycles the organic material for your soil. If it once was alive, it can become compost. Nature composts leaves without our help in forests and grasslands.

Fall was a great season of composting for me and after leaf fall I had 7 piles of compost going. My new home is less conducive to composting the way I used to do it using a tractor with a loader to mix and turn the compost piles at my old farm.  However, I get a little more of a workout turning piles with a fork and I have learned a new way to make compost.

One of our Master Gardeners has introduced us to using stacked bins which appear to work very well.  So many bins are constructed so it is difficult to easily turn the pile from one bin to another. There are also bins which can be turned with a crank, but are not easily loaded or have inadequate holes to permit air to penetrate the compost.

The stacked bins are constructed by stacking 36 x 36 x 6 inch board bin components to contain the compost as in the picture. The boards are fastened at the corners with screws into 2 x 2 x 6.5 inch blocks which will create half inch gaps when stacked. I was fortunate to have salvaged some redwood fence boards and have repurposed them to make compost bins. Any width board from 5 to 7 inches can be used.

It is easy to turn a pile by just moving each bin segment and then filling it using a fork. Material is forked and turned into the new bin location until the pile is totally moved and aerated. Aeration is important to make the compost breakdown faster.  Of course materials will breakdown without aeration, but it takes a long time for that to happen. For quick compost, weekly turnings are good. However, it will not breakdown if moisture is not present, so keep moisture present at about the level of a wrong-out sponge.

What do you need to make compost? Composting occurs best when the ratio of carbon components and nitrogen components are about 30 to 1. Efficient composting depends upon a well-balanced mix of ingredients, which generally fall into two categories: ‘browns’ (high carbon), and ‘greens’ (high nitrogen). Mixing fresh lawn clippings, a green source which is about ratio of 20:1 with leaves which are about 60:1 will make an ideal mixture.

However, fresh lawn clippings are not always available in the fall when leaves are coming down. Instead, I recommend, and I use, coffee grounds collected from a local coffee shop to mix with the leaves. Coffee grounds are about 2 percent nitrogen and make a good source for green material along with vegetable scraps from the kitchen. Coffee grounds are a ‘green’ material that is, in fact, colored brown. Coffee grounds can also be used as a fertilizer, but I find them more useful to make compost. There are some things that are organic, but should not be in a compost pile: noxious weeds, Bermuda grass, pet feces that may cause disease, bones or meat and dairy products that might attract varmints.

Reminder: The Master Gardeners and Master Food Preservers are holding their Smart Gardening conference on March 3 from 9:00 AM to 4:00 PM. It is a bargain at $25 which includes lunch and an all day long program to help you garden smarter and better. The keynote speaker is  Ernesto Sandoval, Director, UC Davis Botanical Conservatory who will talk about low water use garden projects.  For more information on workshop topics covered, go to:

If you have a gardening related question, you can contact the UC Master Gardeners at 209-953-6112. More information can be found at:

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Seed Starting Time is Here by Lee Miller

Correction: In last week’s column, the date of the Master Gardener Smart Gardener Conference was listed as March 8, whereas the date should have been listed as Saturday, March 3. For more information see the San Joaquin Master Gardener website.

Why start plants from seeds? It is fun and challenging for one reason. You also have more choices which can also be a learning experience, (one online tomato catalog lists more than 600 varieties—so many seeds to try and so little time!). You can save money as seeds are cheaper than buying plants and one seed package may last a few years and produce lots of plants.

Now is the time of year to think about tomato, pepper and eggplant seeds going into the seed starting pots or whatever you use to start seeds. Also time be planting parsley, basil, thyme and other herbs and flowers too. The best way to do this is using a heated tray or heat mat to provide about 70+ º F soil that is about right for germination. In February, the day length is too short to provide sufficient light, so I put the light on a timer to provide 14 hours of artificial light using fluorescent lights. The light should be kept within 3 inches of the plants as they grow. This will result in robust healthy plants. If you start your seeds on a southern exposure windowsill you can grow plants, but they will likely be scrawny as they reach for light this time of year.

Getting the right soil for seed starting is important. I have used some commercial seed starting materials and found them lacking in fertility which requires adding fertilizer as the plants grow. It is important to use a seed starting medium and not potting soil which works best for container plants, but not for seed starting. I have used screened fine compost that I have produced for seed starting and have had excellent results with it. Compost will feed the plant until planting time without the need to add a fertilizer. I have never sterilized the seed starting medium as some recommend and have not had any serious problems with damping off fungus which attacks plants just above the roots. Part of the reason for this may be keeping soil temperatures warm and definitely not overwatering.

You can make your own soil mix and I am always tempted to experiment, but using pure compost has worked for me for so many years, so I don’t try something different. However, here a mix recommended by University of Michigan Extension: “Mix one-third part sphagnum peat moss or coconut coir fiber with one-third part finely screened compost and one-third part vermiculite and add about 1 to 2 cups of worm compost to a 5 gallon bucket of this soil mix.” The vermiculite will help hold water as does the compost. The worm compost is a good nutrient source.

Whatever the soil mix used, it is important to have a deep soil mix because you are growing roots that will support the plant after transplanting. I usually start my plants in half gallon cardboard cartons that milk and fruit juice come in. I save them all year and then cut out one side and punch holes near the bottom for drainage. This provides a 4 inch deep rooting zone for healthy root growth. I transplant from these containers to 4 or 6 inch deep pots to ready them for sale or transplanting to the garden. A lot of commercial kinds of materials are available for seed starting.

After transplanting you can put the plants outside during daytime in March and bring them in at night if frost threatens. In most years, you can get by without frost in March, but it is good to pay attention to the weather reports, just in case and move them inside if frost threatens. Being outside will toughen up your plants and ready them for planting in the garden.

Garden Reminders: If you haven’t pruned your roses or fruit trees do it now and that goes for perennials like sages and Artemisia too. Also time to plant any artichokes, asparagus and strawberries or other bare root plants. Valentine’s Day is about the last chance to spray peaches and nectarines for peach leaf curl, a fungus that can cause all your new leaves to be deformed and drop off. It can affect young green shoots as well. Spray all sides of branches and trunk where the fungal spores may lurk to infect the buds. Available fungal fixed copper spray products contain a copper metallic equivalent rating on the label and the higher this number the more effective the product. It is advisable to add a tablespoon or two of horticultural oil to the spray to help make it stick better and provide better protection. Happy Gardening.


If you have a gardening related question, you can contact the UC Master Gardeners at 209-953-6112. More information can be found at:


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  • Blog Authors

    Lee Miller

    Lee Miller is a University of Delaware graduate and retired fisheries biologist, he gardens on 10 acres and makes wine each year with the help of a cadre of friends. However, his first love is gardening and he grows various fruit trees, heirloom ... Read Full

    Marcy Sousa

    Marcy Sousa is the San Joaquin County UC Master Gardener Program Coordinator. She is a Stockton native and enjoys teaching others about gardening. She has her bachelors from Stanislaus State in Permaculture. She has been with the program since 2007. Read Full

    Nadia Zane

    Nadia Zane is a UC Master Gardener, a landscape designer and Stockton native. She has a fondness for California native plants and sustainable landscaping, which she utilizes in her work for Native Beauty Garden Design. She is a member of the CA ... Read Full
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