When designing drought-tolerant landscapes, my clients often request edible gardens for growing fruits, vegetables and herbs. While most edible crops need more water than the most drought tolerant plants, with the right techniques even edibles can conserve water. Water is a precious resource, and there is no better way to use it than to grow your own produce. Raised beds with drip irrigation, are very efficient in terms of space and water use. Harvesting rain water and storing it in a cistern (a large water tank) and connecting it to the drip irrigation system, is the most sustainable source of water for vegetable gardens. Another way of looking at growing your own produce at home, is that instead of wasting water on a lawn, you are using water to grow plants that serve a greater purpose, making every drop count. In preparation for your Spring vegetable gardens, here are some tips to keep in mind about methods of planting, and water usage that will conserve water, and help produce a high yield from your crops.
Healthy Soil and Mulch
The most important element in a water-wise garden of any kind, is healthy, living soil. Healthy living soil acts as a sponge, holding up to 7 times it’s weight in water. Add generous amounts of compost to your soil to boost it’s water holding capacity, and mulch all of your perennials (such as herbs and artichokes) and trees with 4-6 inches of shredded tree trimmings, available for free from tree trimming companies. Find mulch through https://www.chipdrop.in/.
Plant Trees Near Swales
If you are looking for a low maintenance solution to growing food, planting trees is one of the best ways to help combat the drought and grow food at the same time. Fruit trees that originate from the Mediterranean regions of the world such as pomegranate, fig, mulberry, and one of my favorites, feijoa aka pineapple guava, are less thirsty than tropical fruits such as avocados and bananas. If you create a swale, more information can be found in this free book, the water from your downspouts can be directed into the soil, rather than a rain barrel. Every landscape should be contoured to receive the rainwater. That means NO FLAT YARDS! The tree roots will grow out to take advantage of the moisture in the soil. If you want to try this in your garden but want help, please contact me to set up a landscape design consultation. I love working with people who want to grow their own food.
Rain Barrels or Cisterns
My second tip is to take advantage of rebates to purchase rain barrels. Connect them to your down spouts and tap into a clean, free source of water that your plants will thrive on. Chemicals in tap water can actually inhibit growth overtime, where as rainwater will wash out the build up of salts in the soil, boosting plant growth and productivity. Check out TreePeople for great information and workshops on rain barrels https://www.treepeople.org/rainbarrels. If you have a very large roof area you might consider a Cistern, which is a large tank that can hold water and be connected to you drip irrigation system. You might say that it doesn't rain in Los Angeles, and that you wouldn't collect much. When in fact, on just a 1,000 square foot roof, you can collect 620 gallons of water for every 1" of rain! As of today's date, we've received 16" of rain in Sherman Oaks this winter, which on that 1,000 square foot roof is 10,000 gallons of water!
Drip Irrigation and Smart Irrigation Controllers
Watering edible gardens with a properly programmed drip irrigation system will use far less water than a lawn, keep your plants healthy and produce abundant crops. Companies like https://www.skydrop.com/ promote systems that optimize water use in your garden. I recommend drip irrigation exclusively in edible gardens, except in gardens where people water from their rain barrels. I recommend ½” tubing with emitters imbedded in the line every 6”, 12” or 18”, depending on plant spacing. Netafim makes a great product.
A common misconception many people have, is that outdoor water restrictions imposed by water authorities, will impact their garden watering schedule. However, most water restrictions are specifically aimed to reduce the use of sprinklers, because they waste so much water. This won't affect your drip irrigation timing. Sprinklers are not recommended for edible gardens anyways, because they can spread disease, and create conditions for infection to spread.
Proper Plant Spacing
You can also cut back on water usage by spacing your crops efficiently. Make sure to space the plants close enough together so that they completely cover the soil, thinning as needed to make room as they grow. This is a form of living mulch, the plants shade the soil, which prevents water loss due to evaporation. For example plant faster growing crops like lettuce and cilantro, in between slower maturing ones, such as eggplant and potatoes, thus reducing bare soil exposed to the sun. To add variety in your garden, look into planting drought tolerant heirloom varieties. Some seed companies such as Baker Creek Heirloom Seeds, sell unique varieties of melons, squash, corn, beans, other vegetables, herbs and flowers that are drought tolerant and delicious.