This past summer, the California Department of Water Resources began offering rebates to San Joaquin County residents for replacing existing turf with edibles or ornamental water-wise perennials. These programs, along with a growing sense of ecological responsibility, have inspired many to move into a different genre of plants, leaving behind the familiar Hydrangeas and Bermuda Grass. If your garden has become a “terra incognita” of Deer Grass, Foothill Penstemon, and Texas Ranger, the absence of experience may cause you to revert to familiar watering, pruning, and fertilizing regimens. However, your new landscape may require a new mindset and different cultural practices to keep it healthy and beautiful.
Before you do anything else, get up close and personal with your plants. Determine each plant’s natural cycle throughout the year: Will it drop its leaves in winter? In summer? When does it bloom? Does it like full sun or part shade? Does it tolerate heavy soil? The learning curve is always high for newbies; this is normal, as is the “editing” a new garden receives to determine which plants are best suited to the quirks of your garden conditions.
Besides considering the conditions a plant needs to be happy, there are other aspects of water-wise gardening to think about:
Irrigation is one of the trickiest elements in any landscape, and a new water-wise garden may require you to rethink how you apply water. Many traditional landscape plants are thirsty in our climate, allowing a lot of fudge room for excess water. Low-water plants are not always as forgiving, as they are native to regions with little to no rain during the summer. Most will need some supplemental water, just not several times a week like your lawn did.
How much and how often to irrigate depends on many factors, including plant species, soil type, weather, and much more. Some basic principles include providing water to the entire root zone, and preferably just beyond, encouraging roots to grow outward. Extra water is necessary during the first 1-2 growing seasons to develop a healthy root system, which is essential for future drought tolerance.
See Yerba Buena Nursery’s webpage on plant establishment for more tips:
Mulch is essential to water-wise gardening. All mulches help retain soil moisture, though other benefits depend on the material. Organic mulches such as bark chips are best for most situations, providing organic matter, which improves soil structure. Succulent plants prefer gravel.
Getting the thickness of the mulch right is important as well. Thin layers provide no benefits, whereas thick layers can prevent rain water and oxygen from reaching the soil. Large bark chips (2” or more across) have a naturally porous structure, so a 3”-4” layer is good. Smaller chips and shredded materials are dense, so 2”-3” is about as thick as you want to go.
More information on mulching can be found at:
Pruning is a big topic. However, understanding your plants’ life cycles can tell you a lot about how to prune. Some pruning guidelines will be familiar: herbaceous perennials need to be cut to the ground; winter-deciduous species can be pruned during their dormant period. I recommend pruning water-wise evergreens (plants that retain leaves all year) after they flower, allowing time for pruning wounds to heal before the rains come to prevent stem rot.
Water-wise plants typically despise the shearing we foist upon traditional landscape plants such as Indian Hawthorn and Boxwood, which are better adapted to the excess irrigation necessary for this practice.
Fertilize your water-wise plants only if there is a severe deficiency in the soil. Plants that evolved in lean soils should grow at a moderate pace, so look for fertilizers with low analysis to avoid rapid, weak growth that attracts pests and shortens the plant’s life-span.
For help in reading fertilizer labels see the following website:
More tips on water-wise gardening can be found at ucanr.edu/sites/sacmg/Drought.
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 sjmastergardeners.ucanr.edu.