You Can Food Garden in a Drought
Based on materials prepared by Electra de Peyster, Stephanie Wrightson and Cie Cary, Master Gardener Food Gardening Specialists
We are in a drought. This provides us a number of challenges if we want to food garden. When there are water shortages, there are decisions to be made and actions that we can take.
When planning our food garden, we need to be aware of our “water budget”—that is, any city or county restrictions that are or might be imposed—as well as our household’s water needs. If you are on well water, you likely are very attuned to how far your water supply will go. Even if using city water, it behooves us all to manage our use of this limited resource. Plan like you do for a vacation budget: What savings can you make so that you can food garden (taking briefer showers; saving indoor water for outdoor use; turning off the tap unless absolutely necessary; flushing less; running the washer with full loads, using water-saving appliances, toilets, faucets, etc.; installing a gray water system to irrigate landscape ornamentals; etc.)? Then determine: how far will the savings stretch in terms of your household needs, garden bed size and crop choices? What does your family like to eat (and plant only what they can consume)? You will find more help on our website and on your water utility’s site.
Once you’ve made these determinations and decisions, put water-wise practices in place. Briefly, these practices include:
1. Compost, compost, compost! Add organic matter to the soil. If soil is sandy, the addition of organic matter allows the soil to hold more water. Organic matter also helps open up heavy soil allowing roots to go deeper and find more water at lower depths if there is any. Compost increases soil nutrition which helps plants produce better yields with the same amount of water. Compost will allow you to avoid fertilizers—adding more nitrogen to the soil will only produce more leafy green growth which will increase the plants’ need for more water.
3. Use a drip system. Use a drip system for the most efficient application of limited water. Group plants that have the same moisture needs together on the same valve. Irrigate only as long as it takes to moisten the active root zone. For most crops, the active root zone is 6 to 12 inches. Water, preferably, in the morning or in the cool hours of the evening so that soil stays evenly moist. Don’t forget the drip system once it is set up. Monitor and adjust it, as needed.
4. Be selective.
- Learn about individual plant moisture needs. Consider the water available to support crops through harvest, and grow only the amount and types of vegetables the family will consume. For example, plant two beds of vegetables instead of six; plant four tomatoes instead of ten.
- To get the most out of the water you apply, grow high yielding vegetables like beans, chard, mustard, eggplants, peppers, tomatoes, squash, quinoa and amaranth.
- Avoid crops that need consistent moisture unless a particular variety has been bred to need less water. Most brassicas (broccoli, cabbage, Brussels sprouts, kohlrabi, cauliflower and radishes), lettuce and other greens, beets, carrots and other root crops, celeriac, celery, leeks and onions perform best with regular water.
- Generally, cool season crops are not drought resistant and growing them during the heat of the summer requires lots of extra water to keep them cool.
- Consider the following observations on which crops need the most water and when:
- Some beans and sweet corn need considerable water to produce a good crop. Beans need water most when they are blooming and setting fruit.
- Corn needs water most during tasseling, silking and ear development. Yield is directly related to quantities of water, nitrogen and spacing.
- Peas need water most during pod filling.
- Other vegetables, such as cucumbers and squash, and fruits, such as melons, need water most during flowering and fruiting.
- Tomatoes, peppers and eggplant need water most during flowering and fruiting. (Note that after tomatoes set, they can do very well with reduced water, or even no water after they start to ripen).
- After deciding what to grow, choose varieties that tolerate dry conditions. Look for the terms “drought-resistant” or “drought-tolerant” in seed catalogs or on plant labels (note that “heat-tolerant” refers to above ground air temperature and is not the same as drought-resistant or drought-tolerant). Even these varieties require water. Some water is needed to start seeds or establish a seedling, and to periodically irrigate the plant through the growing season. Selecting varieties that are described as “widely-adapted” in addition to drought-resistant and drought-tolerant also is helpful.
5. Consider days to maturity. A crop needing fewer days to mature requires fewer irrigations before harvest (e.g., 62- day ‘Stupice’ vs. 85-day ‘Cherokee Purple’ tomato). Look for early-maturing or short-season varieties. Days to maturity will vary from one part of the country to another as well as from one microclimate to another.
6. Plant intensively. In deep soil or well-amended soil (compost!), roots have more room to grow deeper and find water if it is present. This will allow you to plant more intensively which also may have the benefit of reducing transpiration and evaporation. Use the spacing recommended in the “Year-Round Gardening in Sonoma County” document as a guide. You may find that planting in mounds versus rows or slightly reducing the recommended spacing allows you to have a productive garden using less water.
7. Eliminate weeds. Weeds compete for water. Be aggressive in removing them from growing areas. Weeds also harbor pests that will take greater advantage of water-stressed crops.
8. Use light-weight row covers. Cover plants as a means to collect dew. Dew drops onto soil and keeps it moist. While using row covers can help prevent insect damage, look under the cover from time to time to monitor plant growth and check for unwanted insects trapped inside. There are certain crops, like squash, that must be (partially) uncovered once they flower to allow for pollination.
9. Use shade. Heat-sensitive vegetables can benefit from being planted where they receive some afternoon shade. Plant them underneath or behind taller plants or consider using shade cloth or purposely-positioned outdoor or beach umbrellas.
10. Use windbreaks. The moisture on leaf surfaces is dried by moving air, causing the plant to need more water. In coastal and other windy areas, windbreaks will help roots keep up with leaf demands.
11. Last, but far from least, determine when it is time to water again. Squeeze the soil in your hand: if it sticks together, it is still moist; if it is crumbly and falls apart, it is time to water. If you have drip irrigation, crushing the soil with your hand to test for moisture is difficult. Alternatively, you can put your finger or a chopstick in the soil near the drip emitter. If moist soil clings to your finger or chopstick, check again tomorrow. If you remove your finger or chopstick and it is dry, it is time to irrigate. Never irrigate before performing this soil test.
You can find more detailed waterwise food gardening guidance on the Sonoma County Master Gardener website. With wise decision-making and by employing water-smart strategies, we can grow our own food during a drought.