- Author: Steve I Morse
Advice for the Home Gardener
from the UC Master Gardener Program
of Contra Costa County
Client's Request: Hello. We would like to plant a shade tree in our backyard in mid-County. We have a fairly shallow well… and am assuming a high water table although we don't have any wet, boggy areas. We have two semi-dwarf orange trees s that we never water and they are productive and sweet. Can you recommend links for some shade trees in these conditions .... such as Crape Myrtle, deciduous Magnolia, and Japanese Maples? Thank You.
MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with a question about tree selection. You didn't say how deep your well is, but the water table is probably deep enough that it won't impact trees in your landscape. Tree roots are generally found in the top 1 to 3 feet of soil, with only some sinker roots possibly venturing deeper. Trees don't usually have tap roots past the seedling stage, but rather grow roots that extend well past the dripline (outer edge of the tree's canopy).
If you have good drainage in your soil, any tree suited for your climate should be fine. To test your drainage, dig a hole about a foot deep. Fill it with water and allow it to drain completely. Immediately refill the hole and measure the depth of the water with a ruler. Fifteen minutes later, measure the drop in water in inches, and multiply by 4 to calculate how much water drains in an hour. Ideally, you should have 1 to 6 inches drainage per hour.
The trees you specifically asked about were Crape Myrtle, deciduous Magnolia and Japanese maple. Crape Myrtles (Lagerstroemia spp.) do well in mid-county. They need full sun and seem to appreciate our hot summers. There are many varieties to choose from. This link is to an article from the Sonoma County Master Gardeners about growing Crape Myrtles: http://sonomamg.ucanr.edu/Plant_of_the_Month/Lagerstroemia_spp_Crepe_Myrtle/.
Deciduous Magnolia may not be a good choice. According to Sunset Western Garden Book, deciduous magnolias with saucer flowers do poorly in hot and dry areas. Deciduous magnolias with star flowers seem to do better, but are very slow-growing, and the variety called Star Magnolia (Magnolia stellata) stays quite small and is usually grown as a shrub.
Japanese maples (Acer palmatum) do best in cool climates and will need partial shade and protection from hot, dry wind in the hotter areas of the County. Morning sun and afternoon shade is best. The varieties with green leaves do better with more sun exposure than the varieties with red leaves or those with lacier leaves.
You might also consider Chinese pistache (Pistacia chinesis). It is well suited for our climate and makes a good shade tree. This link is to another article from the Sonoma Master gardeners: http://sonomamg.ucanr.edu/Plant_of_the_Month/Chinese_Pistache/.
For other ideas, this link is to a searchable database where you can select aspects you want such as shade tree, deciduous, maximum height, etc. https://selectree.calpoly.edu/about. They have good descriptions of the trees, along with photographs.
If after you perform a drainage test you find you have poor drainage (less than 1 inch per hour), contact us again and we will research those trees more suitable for a boggier area. Don't hesitate to contact us if you have any questions.
I hope this information is helpful and you find a good shade tree for your yard!
Help Desk of the UC Master Gardener Program of Contra Costa County (SEH)
Notes: Contra Costa MG's Help Desk is available almost year-round to answer your gardening questions. Except for a few holidays (e.g., last 2 weeks December), we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 2380 Bisso Lane, Concord, CA 94520. We can also be reached via telephone: (925) 608-6683, email: email@example.com, or on the web at http://ccmg.ucanr.edu/Ask_Us/. MGCC Blogs can be found at http://ccmg.edu/HortCoCo/ You can also subscribe to the Biog.
- Author: Rebecca Suzanne
Recently, a friend forwarded me a New York Times article about the nationwide use of California water through the consumption of food produced in the Golden State. The article, based on data from the University of California at Davis and the Pacific Institute, states that the average U.S. resident uses 300 gallons of California water this way, every week.
In the face of the worst drought in California recorded history, my inclination has been to stop growing water-thirsty annuals of any kind, including fruits and vegetables. Yet the Times article gave me pause; I feel confident that I can grow an asparagus tip using less than their stated .22 gallons of water and I most assuredly can grow an onion slice using less than .7 gallons!
Gardeners far wiser than I figured this out a long time ago. The phenomenal Rosalind Creasy - long a proponent of sustainable gardening - wrote a 2014 post on just this topic: “When in Drought – Plant Vegetables”. In her post, Rosalind states that growing the average pound of lettuce commercially uses 15 gallons of water, a pound of tomatoes 22 gallons, and a pound of potatoes 30 gallons. Bio-intensive gardener John Jeavons, Director of Ecology Action and author of the best-selling How to Grow More Vegetables, has demonstrated through years of hands-on research, that organic home gardening uses up to 87% less water to grow vegetables as compared to commercial farming. Contra Costa Master Gardener and journalist Joan Morris offers these additional tips for growing vegetables in a drought:
- Don't spare the compost. Add 3 to 4 inches of compost to your garden beds and work it lightly into the soil. Healthy soil produces healthy plants, which need less water.
- Mulch. Add 3 to 5 inches of mulch on top of beds to help reduce water evaporation. Mulch can be almost anything including dried leaves, aged horse manure, extra compost or straw, not hay. Mulch also will repress weed growth.
- Install a drip irrigation system. Drip systems use much less water than any other form of irrigation, and the plants like it better, too.
- Be selective. Plant only what you like and only as much as you'll consume.
- Consider planting early maturing and short-season crops, which will use less water.
- Plant seedlings close together on an offset pattern, rather than in a row. This configuration uses less water and as the plants grow, they will shade the soil and reduce evaporation.
- Grow high-yield vegetables, such as beans, squash, egg plant, peppers and tomatoes. You'll get more for your water buck with these plants.
- Keep your beds weeded. Weeds not only are annoying, they compete with your plants for water and nutrients, and they are much better at grabbing them.
- When given a choice, plant determinate varieties. Determinate plants grow to a certain size and produce for a specific amount of time. Indeterminate varieties will continue to grow and produce until frost. The determinate types, with their shorter growing season, will use less water.
- Instead of planting seeds and watering the entire bed, start seeds in a tray and then transplant the seedlings into your garden.
- We typically do this with certain plants, such as tomatoes, in order to get a head start on the growing season, but consider doing it with the big seed plants such as pumpkins, corn and squash.
- Use shade cloth to help prevent soil evaporation and prevent sunburn.
- Try dry farming. Many plants, including tomatoes, can be dry farmed. Our Garden will have two demonstration beds this year, growing a number of different tomato varieties.
- For successful dry farming, you want to create a spongy growing medium that will hold water. The best way, Miller says, is to grow a cover crop over the winter and then cut the plants down and work them into the soil.
- If you didn't have a cover crop, then prepare the bed with lots of compost.
- Plant your tomatoes and water them as usual for the first few days to get them established, then water only once a week. Once the tomatoes flower and set fruit, cut off all water. The plants may not look great, but they will produce and some say the fruit will taste better.
So step aside, all you salvias and succulents – my vegetable garden is coming through! My rudimentary rainwater and graywater systems will do their best to keep those veggies hydrated, lots of nutrient-rich compost and a deep layer of mulch will keep them cool and moist, and long, deep sips from a drip irrigation system will fill in as needed.
For additional information on dry farming tomatoes, see http://ccmg.ucanr.edu/files/140321.pdf/span>
- Author: Melissa Holmes Snyder
As we move into August, with its typical dog days of summer, we always need to make sure that the plants in our gardens, edible or ornamental, get the water they need. After back-to-back years of winter droughts in much of the west, it is more problematic this summer. Most California water districts, including EBMUD, have asked everyone to cut back on residential water use by at least 10%.
There are several things that a gardener can do that are fairly painless, and most are not too expensive, to help keep your plants, and your local water district, happy till the hoped-for rains begin later this Fall.
Saving Shower Water
Most home improvement/hardware stores carry five-gallon paint buckets. These work well when placed at the bottom of the shower, for collecting water as it is heating up for your shower.
- Bucket: You will likely go through the captured water in day or two, so you may not need more than a couple of buckets for storage.
- Trash Cans: For storing larger quantities of water, a clean 32-gallon trash with lid, is a good vessel for this. The lid is important because you don't want mosquitos to use your saved "still" water for laying larvae, and without that lid, they will. A new 32-gallon can with lid is available at home improvement stores for under $20.
- Wine Barrels: For more attractive water storage, though more expensive, buy a used wine barrel, which holds 55 gallons. You can by one on the internet or contact local wineries to purchase a barrel that they are "retiring". The wineries will usually sell a used barrel for around $40. You will need to get a plug for the bung hole, the big hole at the belly of the barrel which they use to fill and taste the wine (in the picture to the right you can see the bung hole on the right-side of the barrel). Alternatively you could make a lid out of one end if you cut the top of the barrel off. To make it even fancier, you could add a spigot near the bottom. Or put the barrel on its side, and use the bung hole to fill and syphon water, just keep the plug in to prevent mosquitos.
Drip Irrigation, particularly a with "Smart" Controller is ideal for conserving water for vegetable gardens, perennials, shrubs and young trees. But if the smart controller proves too costly, you can create a drip system that you use manually.
Fertilizers and Mulch
- Use organic fertilizers rather then synthetic fertilizer. It improves the quality of the soil, enabling the water to better move through it to the plants where it is needed.
- Adding mulch around shrubs and trees will help prevent evaporation of water from the soil, requiring less frequent watering.