Open Garden Day at the Learning Landscape

As Master Gardeners, we are committed to educating the general public on sustainable horticulture and pest management practices based on traditional, current, and evolving research. One of the ways we do this is through our Learning Landscape demonstration garden located at the San Joaquin UC Master Gardener office.

We will be hosting our first fall Open Garden Day event on Saturday, October 22, from 9:00 a.m. to noon. The garden is located at 2101 E. Earhart Ave., Stockton, at the Robert J. Cabral Agricultural Center just off Arch-Airport Road. This event is free and registration is not required. Light refreshments will be provided. In the case of rain, this event will be cancelled.

The Open Garden Day will feature pruning, irrigation, and planting demonstrations. There will also be a vermicomposting (composting with worms) display as well as some kids’ activities for young garden enthusiasts. Master Gardeners will also be available to talk about the demonstration garden and to answer questions that home gardeners might have about their own gardens. We hope that attendees will be inspired and leave with ideas of things that can be incorporated into their own landscapes.

The Learning Landscape began in 2008 and continues to expand and change. Over the years, Master Gardeners have transformed the originally barren, rocky site into a lively, vibrant garden. A dedicated team of Master Gardeners maintain and improve the garden throughout the year.  Plants are continuously changing as we learn what grows well here and what doesn’t (our battle with rabbits and voles is never-ending).

The goal of our Learning Landscape demonstration garden is to provide the public with research-based, sustainable gardening practices specific to San Joaquin County that are reflective of a variety of environments and gardening experiences. The garden has plants for different needs, including drought tolerance, color, sun or shade exposure, and height. There are ornamental and fruit trees, flowering shrubs, perennial flowers, California natives, vines, and groundcovers. The garden is home to many species of insects, and plants that attract beneficial insects are planted throughout the garden to eliminate the need for chemical pesticide sprays.

The garden also features many sustainable elements. There are water permeable walkways and decomposed granite paths that allow water to infiltrate into the soil. We use weather based irrigation systems that schedule watering as needed based on the current conditions. A drip irrigation system below the mulch allows for uniform watering throughout the garden with minimal loss of water to evaporation. Regular applications of mulch help to conserve water and suppress weeds; the mulch eventually decomposes into organic matter that is beneficial to the soil. Plants that are selected are low water users and are appropriate for the space provided. As a decorative touch, some re-purposed materials have even been turned into garden art.

The garden is composed of 6 distinct but interconnected gardens. Plant identification signs and educational signs tell the story of each garden section. The featured gardens are:

The All-Stars Garden: This section features plants from the UC Davis Arboretum All-Stars program.

The Foliage Garden: A garden with year-round interest that doesn’t depend on flowers.

The Edible Landscape: Demonstrates how to combine food-producing plants with regular landscape plants.

The Mediterranean Garden: Displays plants from the five regions of the world with climates similar to ours, and shows how to combine them for gardens adapted to our area’s climate.

The Pollinator Garden: This section is filled with flowering plants that provide pollen and nectar for pollinators and other beneficial insects. Something is always in bloom!

The California Native Garden: Highlights a variety of garden-worthy native plants adapted to our region.

We invite members of the public to visit the Learning Landscape, and encourage you to visit multiple times to see how the garden’s features change through the seasons. The garden is open 7 days a week, 24 hours a day. Service animals are allowed; pets are not.

For information on scheduling a private tour for your group or organization, call our helpline at (209) 953-6112. For information about other Master Gardener workshops and events, call our number or visit the UCCE Master Gardeners of San Joaquin County website at






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The science behind colorful fall foliage

Crisp cool air and shorter daylight hours are harbingers of one of Nature’s most spectacular gifts: leaves in all their autumn glory. Fall is a welcome time of transition, when hot temperatures subside and foliage slowly transitions from the vibrant greens of summer to hues such as yellow, gold, orange, red, burgundy, and purple.

A flaming red Liquidambar tree (Photo by Kathy Ikeda)

Although fall leaves might resemble an array of warm-colored paint samples in a hardware store, the beauty of their colors comes from within. Plants contain compounds called pigments in their cells. Each pigment absorbs specific wavelengths of light; the light reflected back is what we perceive as its color. There are several main classes of plant pigments:

Chlorophylls. With a name derived from the Greek words for “green” and “leaf,” these pigments give plants their typical color and fuel the process of photosynthesis. Plants produce chlorophyll when they’re actively growing, but with the onset of fall, a plant’s metabolism slows and chlorophyll production halts; this allows other plant pigments to be visible.

Xanthophylls and carotenoids. These closely-related compounds are responsible for the yellow and orange colors in plants. Some specific examples are carotene in carrots (what else?), lutein in yellow fruits and vegetables, and lycopene in red tomatoes. Such pigments are present in leaves year-round, but are usually hidden by the more plentiful chlorophylls.

Anthocyanins. These pigments also have a Greek-based name, one that means “flower blue.” Their color is pH-dependent and can range from purple to blue to red. Anthocyanins are present in the tissues of all higher plants. Unlike other pigments, they’re produced in leaves only at the end of summer when chlorophyll and other sugars are broken down in the presence of bright light. (That’s why the reddest leaves and fruits such as strawberries are the ones with the most sun exposure.)

Vibrant leaves of a Liquidambar tree (Photo by Kathy Ikeda)














Most plants with vivid fall color are deciduous, meaning that they lose their leaves during the dormant season. There’s a reason for this: the process that halts a plant’s chlorophyll production during the shorter days of fall is the same one that helps conserve a plant’s energy reserves and shuts off the flow of nutrients into the leaves.

California can’t match the stunning fall foliage displays of the New England states, but there are plenty of plant species that can be used to add seasonal color to our landscapes. Here are a few outstanding plant selections for our area:

  • Chinese pistache (Pistacia chinensis): This tree performs spectacularly in our climate, with attractive leaves that turn vivid hues of red and orange before falling.
  • Maidenhair tree (Ginkgo biloba): This slow-growing tree is known for its rich golden-yellow fall foliage, which drops en masse when spent. Choose a non-fruiting specimen.
  • American sweet gum (Liquidambar styraciflua): The messy “stickerball” seedpods and invasive roots of this tree can be a nuisance, but its multicolored fall foliage is stunning, especially in California-developed varieties such as ‘Palo Alto,” ‘Festival,’ or ‘Burgundy.’
  • Japanese maple (Acer japonicum): There are countless named varieties of these beautiful trees; their delicate leaves have fall colors in a wide spectrum of warm hues.
  • Persimmon (Diospiros kaki): This tree’s leathery leaves turn yellow and orange, and the bright orange fruit persists as ornaments on bare branches.
  • Smoketree/smokebush (Cotinus coggygria): A small tree or large shrub. Some varieties have unusually colored mature foliage (lime green in ‘Ancot;’ burgundy in ‘Royal Purple’), but the leaves of nearly all varieties turn yellow-orange, orange-red, or scarlet in autumn.
  • Heavenly bamboo (Nandina domestica): This evergreen shrub has many cultivars, but some (including ‘Firepower’) develop pretty red leaf color in response to cold exposure.

October and November are best months to purchase plants for fall color. Individual trees or shrubs of the same species can differ greatly in the colors they produce — one plant might be intensely colored, while another might only produce a subdued display. Shop for plants during their period of peak color to be certain of selecting your favorite palette. Place them in the ground immediately so that their roots can grow in still-warm autumn soil, then sit back and enjoy!

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


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Diagnosing Plant Problems Is Key to Success

Blossom end rot on tomatoes resembles a disease, but is actually caused by calcium deficiency.

Every gardener encounters problems at some point. Nature is our host, greeting gardeners’ hubris with humble pie served by drought, disease, and pest invasions. In the old days one could blame ignorance for missteps in managing pests and diseases; fortunately, our increased understanding of nature’s rules has allowed us to move beyond “spray and pray” and into the role of conscientious gardeners.

Becoming conscientious is not always easy. When we see sad plants, our automatic reaction may be to apply one or both of the supposedly universal panaceas: water and chemicals. Taking the time to diagnose plant ailments can require patience and perseverance, but understanding why problems happen helps increase your chances of success and prevents future mistakes.

Reducing the misuse and overuse of pesticides and herbicides is another advantage to accurate diagnoses of plant problems. If you think your tomato has a fungal disease and it’s actually suffering from a calcium deficiency (blossom end rot), spraying fungicide is ineffective, a waste of money, and introduces potentially harmful chemicals into your garden and food.

Solving plant problems means accepting the garden as an ecology with numerous interconnected elements to consider. A classic example is black sooty mold, a leaf-dwelling fungus resembling its name. Sooty mold grows on the sugary secretions left behind by aphids, which are placed and protected by ants, which harvest the sugar for food. Fungicide won’t help much if the cause (ants and aphids) stick around. In this example, an ecological approach would call for eliminating the ants and spraying the aphids off the plant with water, thereby reducing the sooty mold’s “habitat.”

Knowing why plants droop or get eaten can seem overwhelming at first, and the list of potential causes is sizable. It might ease your mind to know that 90% of plant problems are water-related, either directly or indirectly. The vast majority of gardeners overwater, saturating the soil and creating an anaerobic environment that starves roots of oxygen. Another common mistake is watering a little bit everyday, resulting in drought-prone shallow roots.

A good place to start is identifying the plant species. Plants typically have associated problems, and knowing the species can help you narrow down the causes and management strategy. If you need help identifying your plant, you can go to an independent nursery or contact your local Master Gardener program (a free service). The UC Integrated Pest Management program is an excellent resource, offering visuals of different plant problems and least toxic management strategies. Their website can be found at

Where you go from there is dependent upon the situation, but factors to consider are the time of year, the weather, diseases and pests the plant is susceptible to, and where on the plant the problem is occurring (all over or confined to one part of the plant). You might also think about non-biological causes, such as accidental pesticide exposure, “blade-itis” (damage by mowers, weed whackers), or burns from a heat-reflecting wall. A final tip is to always check the soil if in doubt about whether to irrigate. A drooping plant can be a sign of too much water or not enough, and the top 1”-2” of soil may be dry even if there is plenty of moisture below.

If the UC Integrated Pest Management website seems overwhelming, try their diagnostic tool at Providing information such as the plant species, which parts of the plant are affected, and the type of damage, allows the diagnostic tool to identify one or more causes. This makes a good starting point, especially for those who are new to identifying plant problems.

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 at

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Autumn garden chore time is here

An enjoyable chore-cutting Dahlia bouquets. Lee Miller photo.

An enjoyable chore-cutting Dahlia bouquets. Lee Miller photo.

It is time for fall plantings of all kinds of vegetables. In August, I started lettuce, fennel and onion seeds in flats and I also direct seeded beets, collard greens, lettuce, fennel, turnips, kale, carrots and Kohlrabi. Bok choy and Chinese cabbage are other good fall vegetables. The broccoli, cauliflower and cabbages I had planted in flats in early July had more failures than successes, so I replanted them and recently transplanted them to the garden. I hope they can make a crop because timing is important. Get them started too late and they don’t always grow sufficiently before cold weather to produce a crop. Last year the plants I bought at the nursery did not do well because they apparently were started from seed too late. However, it is worth the gamble to grow a winter garden. Garlic and peas should be planted in early October and onion sets around November 1 or earlier if available. California is a paradise for gardeners because vegetables can be grown year around.

Fall is always the best time to plant shrubs and landscape trees. The cool winter temperatures and rains will give plants time to grow roots and become established, before the challenging heat of next summer. If you love fall colors of red or gold on your trees then some good ones to plant are: Chinese pistache, Gingko, Tupelo, scarlet oak, red oak, Japanese maple, red maple, crepe myrtle or redbud.  It is a good idea to make sure that any mature trees will fit into your landscape space and not be a problem for service lines.  PG&E has a good tree guide book for the right tree in the right place that you can order free from PG&E:

It is also time to plant bulbs, perennials, annuals for winter/spring blooms. With cooler weather, you can plant perennials such as: foxglove, Geum, Penstemon, Salvia, yarrow, Delphinium, Coreopsis Gaillardia, and Campanula and annuals such as: snapdragons, larkspur, ornamental cabbage and kale, Iceland poppies, primrose and stock.  Keep soil moist before the rains start for success and optimal growth. Order your spring blooming bulbs early for best selection and to get them in time for October planting. There are early, mid-season and late-season choices in most bulbs so you can extend bloom enjoyment by careful selection. Narcissus come in a wide variety of shapes and colors and is my favorite because, once established, they come back abundantly every spring; unlike tulips which are generally planted as an annual. Some other choices are: anemone, calla, freesia, Hyacinth, Muscari, and Dutch iris

Prune any low branches from your citrus to discourage fungus infection on the fruit. Cut off branches lower than 18-24 inches above the soil and clean up fallen leaves, old fruit or other organic matter and then mulch with wood chips or bark to keep fungus spores from infecting low hanging fruit when it rains.

Fall is a good time to divide perennials if they are overcrowded. They will grow and bloom better when not crowded. Ornamental grasses Iris, Shasta daisies, Solomon’s seal, yarrow, daylilies; Agapanthus and cannas are just a few which need periodic division. They can be dug up with a spading fork or shovel and then divided with a sharp knife, saw or spade. Replant ASAP or give some extras to friends or neighbors.  Add compost to make up for any lost soil volume and discard any unhealthy plants. For more tips on division of plants see:

Roses will be coming into the fall bloom period although if you dead-headed them frequently you likely enjoyed some roses all through the summer. Final feeding for roses should be in October and it is best to give it either compost or 0-10-10 fertilizer as nitrogen will encourage tender, frost damage-prone shoots. Renew the mulch for winter and avoid fertilizing again until spring.

After two hours work---A full wheel barrow of weed trees and Camellia trimmings. Lee Miller photo.

One of my garden rules is to ‘pay attention’. When you don’t ‘pay attention’ plants can die for lack of water, weeds can take over; lots of things can go wrong. One recent Sunday morning I decided I needed to trim back a Camelia from the doorway to my wine cellar, because I would soon be opening it to bottle wine. As I started trimming, I noticed that there were many seedling trees growing under the Camellias. I spent two hours digging out walnut, pecan, privot, bay, Virginia creeper, and Algerian ivy seedlings from under the Camellias. Some had obviously been there for a long time, but I hadn’t payed attention. Some chores can come your way when you are not even looking for them. I went on to prune dead wood and stray branches from the Camellias and ended up with a wheel barrel of clean up stuff for my unscheduled morning’s work. Gardening often can surprise like this, it seems. Happy autumn gardening!

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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Irrigation 101: Back to Basics

Plants or objects such as this boulder can block sprinklers, leaving dry patches on the other side.

Few elements surpass water on your plants’ list of requirements. While some plants aren’t terribly picky about their watering schedule, some are more exacting and dislike irrational irrigation choices. The added complications of drought and water restrictions are enough to make your head spin. Can’t we simplify and pop outside to water whenever there’s nothing interesting on television?

Besides the rampant overwatering this would cause, we would be robbed of the opportunity to become better acquainted with the needs of our foliaged friends. Their first self-affirmation will likely be that they have genetically hardwired watering needs independent of television programming. Self-affirmation number two will be that opposites do not attract; mixing high- and low-water plants makes for poor relationships. Meeting the needs of one will inevitably sacrifice the other.

In the past, guesswork was the home gardener’s method of choice for grouping plants. Times have changed, especially with tight water budgets calling for more informed choices. Fortunately, the UC Department of Agriculture and Natural Resources (UC ANR) has conducted research that groups plants into high, medium, low, and very low water needs. These are further divided into the six major climates of California. This information is available on a searchable database at

Irrigation is much more efficient and effective when all the plants on a circuit (AKA “valve” or “station”) need the same amount of water. You may need to do some “editing” of any mismatched planting beds before going on to the next major part of good irrigation, which is a well-designed and functioning system.

There are many different kinds of irrigation, but we can simplify a little by dividing them into two basic categories: drip and spray. Turf grass is almost always irrigated by spray; the trick is to get even coverage and apply water in the right quantity and frequency. When designing a system, make sure the spray of one head reaches to the next head, called “head-to-head coverage” in irrigation lingo. This is important because the area immediately around sprinkler heads gets most of the water, while the outer two-thirds of the spray area get less. To prevent dry patches, overlap the spray areas for even water distribution.

Avoid playing “hope and poke” with your irrigation timer by gathering information. Observe the sprinklers in action and make appropriate repairs or adjustments. Check to see how long the sprinklers can run before water starts puddling or flowing onto sidewalks. Determine the output of your sprinklers by performing a catch can test (see the following website). A handy tool for irrigation scheduling and general lawn care is available on the UC Guide to Healthy Lawns website at

Both drip irrigation and spray can be used on ornamentals and edibles, though drip is usually recommended wherever possible because of its efficiency rate of up to 90%. Drip systems consist of flexible tubing that runs above ground, delivering water in drips that infiltrate slowly to prevent run-off. Like spray, drip irrigation systems must be properly designed and installed to be effective. In addition, they require more frequent inspections, especially if the system is subject to wildlife, pets, or children. Regular inspection of the lines and emitters will help ensure that dead plants are not the first indicator of chewed lines or an emitter that has been knocked out of place by a game of dodgeball.

Water conservation is another important component of your irrigation system. Watering deeply but infrequently is better than daily, shallow watering, which forces plant roots to grow at the surface rather than deeper in the soil where they become more drought-resistant. Organic mulch (e.g. bark) placed on the soil surface reduces evaporation and feeds the soil microbiome, all of which makes for healthier plants.

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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What is Integrated Pest Management?

What is Integrated Pest Management?

Integrated Pest Management (IPM) is an approach to prevent pests or manage pests in a less harmful manner than just reaching for a toxic chemical. It was developed by scientists in the 1970’s and the University of California program started in 1979. IPM helps homeowners, gardeners and farmers deal with pests in a manner that is the least damaging to human health and to our environment. IPM likely got its impetus from Rachael Carson’s 1962 book ‘Silent Spring’ which brought serious attention to the impacts of widespread pesticide use on our environment, wildlife and us.

IPM has several components thus the term integrated. First of all is correct identification of the pest and monitoring its impacts. You need to know what creature or disease you are dealing with to select a winning strategy to control it. Pests can include weeds, vertebrates, invertebrates, insects, bacteria, viruses and fungi. If the pest does no economic damage, is it even a pest?  If it is not harmful, nothing needs to be done.

Prevention by the selection of plants that are resistant to diseases or pests is a good starting place. For example older cultivars of Crepe Myrtles (Lagerstroemia spp) are highly susceptible to powdery mildew, but newer cultivars, some with Native American names, are bred for resistance and don’t require treatment for powdery mildew especially when planted in the sun and properly pruned to keep them open. Some resistant varieties are: Catwaba, Kiowa, Hopi, Natchez and many others see:

Most peaches are susceptible to peach leaf curl, a fungus which requires preventive spraying during the dormant season. Most people either forget to spray, or they lazily hope for the best—like a dry spring that inhibits the fungi. There are a few varieties resistant to peach leaf curl and they are Frosty, Black Boy, Muir, Avalon Pride and Indian Free.  If these varieties don’t suit, then plant others and vow to spray for peach leaf curl. Plant breeders are busy breeding disease resistant roses, tomatoes and many plants that we can enjoy and avoid pest situations. This is the first line of defense against pests.

Another IPM practice is biological control which is to encourage the enemies of pests. Creating a diverse landscape that provides habitats and food for natural enemies of pests is a good practice and not indiscriminately spraying pesticides that kill them is a paramount consideration. Some beneficial insects that are predators on pests are lady beetles, lacewings, spiders, soldier beetles, syrphid flies and mini-parasitic wasps. The mini-wasps parasitize aphids and caterpillars. For more info on beneficial insects, see: .

For many pests, physical barriers or mechanical removal will work to keep them at bay. For example, ants will invade your home for water and food. One way to keep them out is to eliminate any access by caulking openings or removing any vegetation that they use as a highway into your home. Ant bait traps that work to kill ant colonies are another method. For aphids, a stream of water will wash them off rose buds or plant leaves without resort to pesticides. Since aphids can return rather quickly this should be done as frequently as needed at least twice per week.

Barriers such as using old toilet paper rolls wrapped around young plant stems will work for cutworms if you should have that problem. Similarly bird netting works to keep birds from picking your fruit before you get a chance. Every year, I have to cover my half acre of wine grapes with bird netting, an onerous, but necessary chore if I want to make wine. Raised beds are a common way to garden these days and if you want to keep gophers at bay, it is wise to line the bottom with gopher wire or hardware cloth.  I don’t have this situation, so I constantly have to trap gophers with McCabe traps and oft times suffer damage before I catch them. Deer, ground squirrels and rabbits can also be garden nuisances. Fencing off the garden or trapping are ways to deal with them.

Another way to control pests is to follow good gardening practices. Cleaning up debris and composting will eliminate hiding places for pests and keeping weeds under control will avoid the buildup of weed seeds in the soil. Soil solarization can also reduce the weed problem see:  Be sanitary and remove infected plant material such as black spot infected leaves from under roses or petal blight infected blossoms from Camellias to diminish sources of disease causing organisms.

When all else fails one can use pesticides, but use the least toxic one that will get the job done. Follow directions on the label and use in ways that reduce human, pet and environmental exposure. IPM works well and I hope you will learn more garden tips at this informative website for gardeners:

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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Basic tips for houseplant care

Some people have a magical touch and homes overflowing with thriving greenery; others just can’t seem to keep an indoor plant alive. Even if you’re cursed with a “black thumb,” there’s still hope.

Houseplants are incredibly diverse, and although some come from climate zones like ours, most popular species are native to warm, humid, tropical environments. Houseplants are typically grown for their foliage, which can range from tiny to huge, lacy to leathery, rich green to variegated or multicolored. Some are grown for their spectacular and vibrantly colored flowers. With such diversity comes a wide range of specific cultural needs, but a few simple guidelines will help provide a measure of success.


Overwatering is the primary cause of houseplant death. Symptoms of overwatering—yellowing foliage, droopy appearance—often mimic those of under-watering, so it’s important to check soil moisture using weight or visual tests, a soil moisture meter, or a simple finger probe. If the soil is heavy, dark in appearance, or damp an inch or more below the surface, it’s probably moist enough. On the other hand, severe lack of water is also harmful, and plants will perish if allowed to wilt repeatedly.

Frequent watering with small amounts of water is detrimental to potted plants; instead, water them less often and more thoroughly, until water passes through the drainage holes. Solid-bottomed pots must be watered cautiously to prevent waterlogged soil. Most houseplants need more water while actively growing in spring, summer and early fall; water more sparingly in the late fall and winter. Some houseplants are highly sensitive to fluoridated water; others don’t like cold water. Never use softened water since it contains high levels of damaging salts.


This is the second of the two most crucial elements for houseplant care. Depending on their natural environment, houseplants vary greatly in the amount and type of light they require. Natural light from windows is preferable, but full-spectrum fluorescent lighting can be a good substitute in dark indoor areas. Some plants prefer only diffuse, indirect light from north- or east-facing windows; others can tolerate bright light or direct sunlight from south- and west-facing windows. Be sure to research the individual lighting needs of your plants, and to locate them appropriately.


Purchase a high quality, commercially prepared, sterile potting mix that is suited to the plant(s) you own. For most tropical plants, an all-purpose potting mix with some organic matter will suffice. For plants such as African violets that prefer acidic soil, use a specially labeled mix or one high in peat content. For succulents or cacti, use a product specifically labeled for them since it’s lightweight and fast draining and will dry out between waterings. Don’t fill pots with compost (which is a soil amendment) or garden soil (which is too dense).

Examine the soil and the rims of your pots for white, crusty-looking deposits; this indicates a build-up of harmful salts in the soil (from fertilizers or minerals in the water). To remedy this problem, scrub the pots and either replace the soil or thoroughly flush it with water. Most houseplants should be repotted with fresh soil every few years. Don’t reuse old soil, since it could be contaminated or nutrient poor.


With the exception of dry-environment succulents, houseplants generally don’t thrive in dry indoor air unless given some special care. Many plants appreciate a gently daily or semi-weekly leaf misting. Plants can also be placed in bathrooms or on trays filled with small pebbles and water so they get additional moisture.


Daytime temperatures between 65 and 75 °F are acceptable for most houseplants, with slightly lower temperatures at nighttime. Keep plants away from the hot, drying drafts from heater vents and the cold blasts of winter air from doors, windows, and air conditioners.


All potted plants need fertilizer to replace lost soil nutrients. Plants that are fast-growing, frequently watered, or in fast-draining soils should be fertilized more often. Slow-release fertilizer pellets and water-soluble fertilizers are the easiest to use on indoor plants. Follow label instructions to avoid harmful over-fertilizing, and avoid fertilizing plants in late fall and winter when their growth slows.

Pests and Diseases

Minimize houseplant problems by using a few simple precautions. Carefully inspect a houseplant’s leaves, stems, and soil before purchasing. If you see any signs of common pests (mealybugs, scale insects, whiteflies, spider mites) or diseases (stem rot, leaf spot, soil fungi) don’t bring that plant home. Care for your plants properly, because stressed plants are more susceptible to attack by harmful organisms.

Space limitations allow only the most basic overview of a very complex topic here. For more detailed information on the needs of specific houseplant species, please consult reputable books or online resources.

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


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Gardens as refuges for wildlife

This coming Sunday, September 4 is National Wildlife Day. While this name might conjure up images of animals living in pristine natural areas and parks far from home, wildlife can (and should) be an important component of our gardens.

The San Joaquin Valley used to support vast herds of tule elk, sky-darkening flocks of migratory birds, plentiful native salmon, and even our state mammal, the California grizzly bear. These and numerous smaller creatures have largely been lost or displaced due to urban development, large-scale water diversion, and monoculture farming. Yet even in this highly altered environment, our residential and commercial landscapes, public gardens, and agricultural areas have tremendous potential for supporting a wide array of small local fauna.

Habitat diversity is one key to the survival of wildlife, and we can help provide that diversity by creating miniature ecosystems in our yards.

Just like humans, animals have a few basic needs for survival: water, food, shelter, and places to raise their offspring. Plants are essential to meeting these needs. They provide seeds, berries, nectar, pollen, and succulent fruit for nourishment; they bear foliage in which birds and small animals can hide and/or build their nests; and they’re a source of moisture, shade, and nesting material.

Wise plant selection is a crucial element of a wildlife-friendly environment, since it determines the number and variety of creatures a yard can support. Plants that originally grew in our area—native oaks and grasses, sages, buckwheats, penstemons, and many more—are the best choices for wildlife because they evolved alongside our California animal species and are best suited to their needs. Plant species imported from different U.S. regions or countries can be beautiful and useful in their own way, but some are far more wildlife-friendly than others, so they must be chosen carefully if they’re to provide for our indigenous fauna.

Sunflowers are one outstanding choice for attracting wildlife such as pollinators, beneficial insects, and birds. These annual plants add color to my backyard garden every year, and they hum with activity from spring through fall. When aphids take hold on spring’s succulent new leaves, so do the ladybug larvae. Once the vibrant and cheerful blooms appear, so do the pollinators; honeybees, bumblebees, several other types of native bees, and five species of butterflies have visited my plants this year. Come summer and early fall, dragonflies occasionally use the tall stems as a roost, young praying mantises hide and hunt in the plants, and the ripening sunflower seeds attract small birds such as juncos, finches, and grosbeaks. It’s both educational and entertaining to watch the seasonal show.

Lesser goldfinch at native sunflower (Photo by Kathy Ikeda)

There are many other ways to make inexpensive and wildlife-friendly additions to an existing landscape. Solitary native bees appreciate an elevated, open patch of soil or a wooden bee box in which to nest. A cluster of boulders near low-growing shrubs will give insect-eating lizards a place to sun themselves and hide. A rock wall or large boulders will provide denning spots for beneficial non-poisonous garter and gopher snakes (which help control pest insects, snails, slugs, and rodents). Frogs and toads will thrive near a small, shallow pond surrounded by moisture loving plants. A birdbath will provide much-needed water for birds and insects; locate it under an arbor or tree to shield small birds from sun and predators, and place a flat stone just above the water level to give butterflies and bees a place to land.

Bee houses on display at the UCD Arboretum (Photo by Kathy Ikeda)














A wide range of plants sizes also helps to nurture wildlife. Large trees with understory plantings of shrubs and groundcovers provide better habitat for animals than a landscape with only isolated trees and shrubs near a patch of lawn. Homeowners and farming operations can employ this principle of habitat diversity by creating hedgerows along property boundaries. Hedgerows are mixed border plantings that incorporate varied annual and perennial plants, with the specific goal of providing for beneficial wildlife.

For more information on supporting wildlife in your garden, consult these resources:

(September 4 is also National Newspaper Carrier Day! Consider giving your neighborhood carrier a word or token of thanks.)

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

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Improving Soil Health With Cover Crops

This taprooted Daikon radish does double duty by breaking up heavy soils and being delicious.

Cover crops are plants grown for the direct benefit of the soil rather than human consumption. They were known in ancient China and India and have been standard practice in many agricultural regions of the world, including colonial America. This changed in the 1940s when our WWII infrastructure was redirected toward the production of fertilizers, pesticides, and other chemicals that replaced traditional land stewardship practices.

In its own way, the “Green Revolution” cushioned humanity from nature’s attempts to sabotage our tomato beds, and it certainly increased global food production. Unfortunately, the environmental and human health costs begged for better solutions. Before long, we saw the return of traditional (but improved) cultural practices such as cover cropping, which offers better living through biology.

Building soil health and fertility are the main reasons for using cover crops, but the benefits don’t stop there. The soil’s many organisms play a major role in plant vitality, and they love cover crops, which they use as food. This recycles important nutrients, particularly nitrogen, back into the soil for future plant use. Over time, the increased biological activity improves soil’s structure, and water and nutrient holding abilities.

Creating balance is another key to healthy soil, which cover crops achieve in several ways. They break up the cycle of pests and diseases that accumulate when plants within the same family (e.g. tomatoes and eggplant or cucumbers and melons) are grown too many times in a row. The habitat cover crops provide is beneficial to a diversity of creatures, preventing any one species from becoming a pest. You even get a natural weed block, as many weed seeds cannot germinate through the thick mat of cover crops.

Selecting your cover crop takes some research, but it’s usually best to choose a mix to counterbalance drawbacks of any given species. At minimum, you should plant legumes (e.g. fava bean, cowpeas) for a quick release of Nitrogen, and grasses (e.g. winter rye) to decompose more slowly, providing a longer-lasting mulch and slower Nitrogen release. Other cover crops to consider are oilseed radishes whose taproots break up heavy, compacted soil, and buckwheat, which establishes quickly, providing rapid weed suppression.

Using cover crops takes some planning, as you will be growing them in place of food crops. They are an excellent alternative to letting soil lie fallow over winter when rains can leach nutrients out of the root zone or cause erosion. Select a site in full sun and sow seeds in September or October. Water until the rains arrive, and then only as needed during winter dry spells. They won’t need any other maintenance until March, when you cut them down in preparation for your food crops. The exact timing depends on how quickly they begin to set flower, which is when you want to kill them.

Tradition calls for tilling cover crop biomass into the soil. For soil microbes, this is like taking a bulldozer to your house and hosting a dinner party the same day: possible, but not conducive to comfort. Bacteria, fungus, worms, and many other organisms feeding on organic matter exist in different strata of the soil, depending on what stage of decomposition their food needs to be in. Some organisms, especially bacteria, are immobile, so disrupting the soil layers moves many to where they won’t be able to access the food they need. If you feel more comfortable incorporating the cover crops into your soil, organisms will eventually repopulate, but try to disturb them as little as possible.

Four to six weeks before planting your food crop, kill the cover crop with a lawn mower, weed whacker, or string trimmer, cutting as close to the ground as possible. Spread the biomass evenly on the ground as a mulch. At planting time, use a mattock to create planting strips. Food crops started from large seeds or transplants work best.

Other benefits of the “no-till” method include keeping weed seeds buried, and saving you a lot of work. As long as you have legumes, the temporary nitrogen deficiency mentioned above should not be an issue. Selecting annual grasses rather than perennials will help ensure they won’t stick around when it comes time to plant your food crops. Finally, be sure to kill cover crops before they set seeds to maximize nutrient recycling and prevent weed problems.

See the Sacramento County Master Gardener website at <> for information on traditional cover crop methods. 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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Indoor Plants Help Clean the Air

Spider Plants are great for filtering indoor air pollution

Many people are drawn to the aroma of a new car, a recently varnished cabinet in all its unscratched glory, or “spring fresh”- scented cleaners. We may revel in newness and hygiene, but the smells associated with “fresh and clean” are often due to toxins in a variety of household products. When released into the air, these chemicals become indoor air pollution and have been linked to a variety of illnesses, including nausea, asthma, cancer, and neurological, developmental, and reproductive disorders.

While it’s impossible to eliminate them completely, you can reduce levels by choosing products with fewer toxins, and growing indoor plants to filter some of the harmful volatile organic compounds (VOCs) out of the air. If this seems like horticultural hocus-pocus, worry not; indoor plants have proven their worth in many scientific studies that tested some of the most common VOCs such as formaldehyde (paper products), benzene and toluene (plastics, detergents, glue), and ammonia (cleaners, fertilizers).

To get the most out of your indoor plants’ filtration benefits, it helps to know a few factoids. One of the most important things to know is that the foliage has only a secondary role in the removal of undesirable compounds. Most of the action happens in the soil, called the “potted plant microcosm” by researchers, where VOCs are metabolized into harmless byproducts. Carbon monoxide is also taken up by soil bacteria for their metabolic processes, and by plants to stimulate root growth and seed germination.

Unfortunately for those who lack a green thumb, your dead plant coffins (pots of soil with deceased plants) will not keep this microcosm alive. Plants and soil microbes have a mutually beneficial relationship in which plants provide sugars for soil microbes; microbes, in turn, help plants access more nutrients and water.

Another fact to consider is that some plant-microbe teams are better than others at VOC reduction. Examples of great air-cleansers include Boston Fern (Nephrolepis obliterata), Spider Plant (Chlorophytum comosum), Purple Heart Plant (Tradescantia Pallida), Areca Palm (Dypsis lutescens), and Rubber Plant (Ficus elastica). NASA’s list of clean air plants, created after their seminal research of the late 1980s, is easily found with an internet search and provides more plant ideas.

On the flip side to this biofiltration boon, some potted plant microcosms actually emit VOCs as well. Soil bacteria is responsible for some, so plant selection can help. However, most come from cultural practices, which the plant guardian has more control over. Selecting plant species whose needs match your home environment will prevent a lot of problems, as keeping them healthy will be easier. If necessary, use horticultural oils instead of toxic pesticides to deal with pests. Feed with organic fertilizers instead of synthetics; better yet, choose plants with lower fertilizer needs, and place them outside, if possible, when it’s time to feed so that some of the VOCs are gone when the plant is brought back indoors (some plants do not like being moved, so do your homework first). Choosing clay or ceramic over plastic containers can further reduce VOC emissions.

For more information on caring for indoor plants, check out the SJ County Master Gardener website at If you have a gardening related question you can contact the UC Master Gardeners at 209-953-6112.


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    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

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    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

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