Vegetable crops need 1 inch of water each week--as a
general rule of thumb; this is the equivalent of about ½ gallon of water or
slightly more per square foot of garden. Some crops need more water, and some
The best vegetable crop production comes from consistent
watering. It is important to avoid having vegetable plants go dry-then wet-then
dry; this will cause plants to grow in stops and starts. Uneven watering can
lead to uneven production and often uneven appearance and size of vegetables. Vegetables that are under-watered and come to harvest with a low water water content can be bitter or tasteless.
The objective of watering vegetables is to replace the
moisture lost from transpiration and soil moisture evaporation. The goal is for
soil moisture to remain more or less constant--just moist, not wet or dry is
optimal. Vegetables generally need the most water during mid- and late-summer
and when the weather is particularly hot.
It is time to water your garden when a handful of soil
squeezed into a clump falls apart when lightly touched.
One-inch of water each week is the average needed to keep
the soil just moist. In arid or particularly hot regions, about 2 inches of
water each week is required. The amount of water may vary from ½ inch per week
early in the season to more than 1 inch later in the season.
Vegetables that receive too little water (or too much
water) will stop growing. When a vegetable begins to wilt from lack of water,
it has already stopped growing for a day or more. (Temporary wilting of
fruiting crops such as squash and cucumbers on a hot summer afternoon is not
necessarily a sign of inadequate watering--this can be a sign of normal
photosynthesis at its water-demanding peak.)
As each crop grows toward harvest, it is important to keep
the soil evenly moist and allow the crop to attain its optimal water
content--this will make for the best form, color, and taste. Under watering can
leave vegetables bitter; overwatering can leave vegetables tasteless.