Vegetable Gardening During Drought

Temperatures worldwide have been rising. They may continue to rise. Longer and more severe droughts are forecasted. Special strategies are needed by gardeners to deal with increased water needs of garden plants.

Two-feet deep topsoil will stay moist longer than lesser thicknesses. Adding topsoil can be expensive but is one of the more effective strategies. If your soil is already two-feet or more thick, breaking up the soil to a two-foot depth will help roots to grow deep where there is still moisture during drought. One method is to spade away the top foot and use a garden fork to loosen the next foot down.

Adding organic material makes the soil hold more water and so stay moist longer during drought. Organic matter makes clay soil more permeable so there is less runoff and water moves down faster reducing evaporation loss. Preferably, the material should be rotted. Adding too much non rotted plant material can cause the soil to become too acid. The more deficient in hummus, the more should be added. The deeper you mix in the hummus, the more should be added. A two inch layer of compost is often about right.

Choose plants with relatively low water needs. This includes okra, blackeyed peas, asparagus beans, moth beans, garbanzo bean, tepary bean, tomato, and New Zealand spinach. Somewhat tolerant of dry soil are squash, cabbage, snap beans, bok choi, mustard greens, amaranth, and Asian shallots.

Plant fast maturing vegetables in early spring that mature before the weather becomes hot and dry: peas, spinach, leaf lettuce, and short season corn. In the fall grow beets, carrots, and lettuce. Longer maturing fall vegetables can be grown if water is provided for the first six weeks or so: cabbage, brussel sprouts, head lettuce, and broccoli.

Apply water very early in the morning when temperature is lowest and humidity is highest. Less water will be lost to evaporation. Drip irrigation and soaker hoses will have less evaporation loss than sprinklers. A soaker hose can be left in place and covered with straw mulch to greatly reduce the amount of water evaporating from the soil.

Keep the soil moist surrounding plant roots. For tiny seedlings, that will be only the top two inches or so of soil. As plants become larger with deeper roots, water less often but use enough water to soak the soil deeper. Moist soil at the ends of the deepest roots encourage the roots to go deeper where moisture is when drought is most severe.

Four to six inches of straw mulch will greatly increase how long the soil stays moist after a rain or after watering. In general, it may be better to apply the mulch after cool, wet spring weather so as not to give slugs good conditions. If mulch does not seem practical, an alternative is breaking up the top two- to three-inches of soil to form a powdery layer. Wicking action of water through the soil is reduced so underlying soil stays moist longer. Break up the soil using a stirrup hoe or roto tiller after it rains and before the soil drys. The process is sometimes called dirt mulching or dust mulching.

Do thinning of seedlings before the plants crowd each other and there is competition for nutrients and moisture. Do not allow weeds to take water, nutrients, and sunlight.

If transplanting during hot, dry weather, provide shade with whatever seems appropriate: cloth, lattice, newspaper, large leafs, or cardboard. Leave the shade in place for four to ten days depending on conditions. Water often enough to keep the roots moist.

Walk through the garden during the hottest part of the day to watch for wilting. Where needed, apply water, mulch, or shade; or harvest.