Critical watering periods for vegetables. You can target the timing and amount of water to add. As a rule of thumb, water is most critical during the first few weeks of development, immediately after transplanting, and during flowering and fruit production. The critical watering periods for selected vegetables follow:
- Asparagus needs water most during spear production and fern development.
- Broccoli, cabbage, Brussels sprouts, kohlrabi and cauliflower need consistent moisture during their entire life span, especially during head or root development. Water use is highest and most critical during head development.
- Beans have the highest water use of any common garden vegetable, using 0.25 to over 0.50 inches of water per day. Beans need water most when they are blooming and setting fruit. When moisture levels are adequate the bean plant is a bright, dark grass green. As plants experience water stress, leaves take on a slight grayish cast.
- Carrot and other root crops require consistent moisture. Cracking, knobby and hot flavor root crops are symptoms of water stress.
- Corn needs water most during tasseling, silking, and ear development. Yield is directly related to quantities of water, nitrogen and spacing.
- Lettuce and other leaf vegetables need water most during head development. For quality produce these crops require a consistent supply of moisture.
- Onion family crops require consistent moisture and frequent irrigation due to their small, inefficient root system.
- Peas need water most during pod filling.
- Potato tubers will be knobby if they become overly dry during tuber development.
- Tomatoes, peppers and eggplant need water most during flowering and fruiting. Blossom-end-rot (a black sunken area on the bottom of the fruit) is often a symptom of too much or too little water. Watch for overwatering.
- Cucumbers, summer and winter squash, and other vine crops need water most during flowering and fruiting. Watch for overwatering.