- Author: T. Eric Nightingale
Planning a drought-tolerant garden can be a challenging endeavor. Knowing which plants to use and where to plant them is difficult as information and advice can vary significantly. However, there are a few simple things you can do to make the process easier.
The first task is to become intimately acquainted with your garden. Watch the way the sun moves and where the shade falls throughout the day. It may seem obvious that how much sun a plant receives will affect how much water it uses, but not all plants labeled for low water use will thrive in full sun.
Knowing the locations in your garden that receive shade from summer heat can greatly affect the health of your plants and the maintenance required to keep them looking attractive.
Note how wind moves through your garden. Evapotranspiration, the loss of water through plant leaves, increases significantly with high, hot or dry winds. On a cloudy yet windy day the plants in your garden could dehydrate more than you expect.
Finally, get up close and personal with your soil. Check its water retention by digging a hole about a foot deep and wide and filling it with water. Hope for the water to percolate through in about an hour, signifying good drainage.
Many drought-tolerant plants, especially succulents and cacti, will rot if soil drains too slowly. Conversely, if the soil drains too readily, it can be difficult to keep even low-water plants adequately hydrated.
All of these factors will help you form a picture of how water will be utilized in, and move through, your garden. This knowledge is a useful tool when choosing new plants.
When working on creating a drought-tolerant garden there are some preconceptions it is best to discard. When many people think of a garden, the image that comes to mind is of a classic English garden. This is understandable as modern home gardening and many of its traditions originated in Europe.
But England has a different climate than Napa, and it is not realistic to expect our gardens to look like English landscapes.The plants found in English gardens are often not good candidates for a Napa Valley garden, least of all a drought-tolerant one.
Many of the best-known annual plants are thirsty in our climate, as are many popular perennials such as hydrangeas, camellias and gardenias. Tropical plants, while visually stunning, are often troublesome as well. Even if they are not labeled as requiring a lot of water, the relatively low humidity in Napa Valley can make it difficult to keep them healthy.
Changing our expectations for our gardens does not mean lowering them. A garden can use less water and remain visually pleasing, lush and colorful. In a sunny location, shrubs such as salvia and lavender can be placed among large succulents such as aloe and agave. The contrast of soft and sharp textures is pleasing to the eye. The salvia will bloom most of the summer, while many aloe, such as Aloe capitate, bloom in the winter.
Many popular groundcover-type plants have shallow roots and need frequent watering. These can be easily replaced by a clumping or vining succulent. A favorite of mine is ice plant, Delosperma cooperi, which produces a carpet of purple-pink blooms from spring through summer.
Identifying plants that work in a drought-tolerant garden is easy after some practice. Generally speaking, plants with large, glossy leaves are a poor choice. These plants will lose a lot of water to evapotranspiration and are prone to sunburn. Plants with dusty or fuzzy-looking leaves are much more adapted to hot, dry conditions.
The roots of a plant can also tell you something about its water needs. Small, shallow roots will need more frequent watering than large, deep-burrowing ones. Never hesitate to gently remove a nursery plant from its pot and inspect the roots. They are a key indicator of plant health.
An important bit of information often missing on plant labels is the term “once established in the ground.” Succulents excepted, a potted plant will usually need more water and fertilizer than the same plant in the ground. Many drought-tolerant shrubs survive by growing broad or deep root systems. It takes at least a year for new plants to develop a useful root system, during which time they will need additional water.
Knowing these facts about your garden and the plants in them, as well as altering your perception of how a garden should look, can make an enormous difference in your relationship with it. You can minimize required maintenance and reduce your stress, leaving only the pleasure of enjoying the beautiful space you have created.
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Advice for the Home Gardener From the Contra Costa Master Gardeners' Help Desk
Client's Questions & Concerns:
Client called in and also sent email with picture asking whether her aloe needed repotting. Plant appeared to be in original 4" pot. She also wanted to know why the plant was drooping.
Response from the CCMG Help Desk
You want to choose a pot that is wider and deeper than the current plant, with space for the plant to grow. The new pot can be plastic or clay/ceramic. Given the top-heavy nature of an aloe you may want to use a clay or ceramic pot. Any pot you select should have one or more drainage holes in the bottom. You can use commercial cactus mix as your planting medium.
Before planting, lightly cover the drainage holes with a piece of clay or a screen. Note: Do not place pebbles or multiple layers of clay pieces in the bottom of the pot "to improve drainage". Recent research has shown that the pebbles do not improve drainage; they just limit the space for the roots.
To repot, remove the plant from the current pot, clearing away the old soil from the roots. I noticed that you have a "pup" in the corner of the current pot. You will want to cut the pup from the main plant. You can plant it separately if you want. Place the plant(s) in the new pots with the cactus mix. The main plant can be planted with the lowest leaves at the soil level, i.e., with the bare stem buried. Allow the plant(s) to rest out of direct sunlight without water for the first week or two after repotting. This allows time for roots that may have been damaged in the transplanting process to heal.
There are several environmental factors that could be causing the drooping problem. One is water. Aloes should be watered approximately once a week through the growing season (spring to fall). Aloes need less water during the winter, but you do need to make sure that it gets enough water to avoid shriveling. You especially want to make sure that the plant does not fully dry out once you start watering it this winter after the transplant waiting period is over. However, you should let it dry out the top 1-2" between waterings (you can stick your finger and/or popsicle stick to check, etc.).
A second factor is fertilization. The plant looks like it had some sudden new growth. Like many houseplants, aloes do well with regularly applied diluted fertilizer during the growing season, with no fertilizer during the dormant (winter) season.
A third factor is light. Your plant may need additional light. A west or south facing window is best. Care must be used when introducing additional light or moving the plant to a brighter location. The plant should be introduced to the additional light gradually to avoid scorching.
For more information on repotting and growing succulents and cactus see: http://www.csssj.org/welcome_visitors/basic_culture.html.
For specific information on aloes, see: http://homeguides.sfgate.com/plant-aloe-vera-container-80791.html and
for indoor succulents http://homeguides.sfgate.com/indoor-potted-succulents-dying-80564.html.
And for a view of Aloes and other succulents in a garden setting (with some in pots as well in the nursery), you should visit The Ruth Bancroft Garden in Walnut Creek. This is a world-class garden utiliizing succulents and other water-aving plants in settings that can be inspiration for your home and garden.
Good luck with your aloe.
Please let us know if you have further questions.
Contra Costa Master Gardeners Help Desk
Note: The Contra Costa Master Gardener Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/
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