University of Illinois Extension

Watering Tips for Vegetable Gardens

Each vegetable has a critical time in its growth when lack of adequate moisture can be a severe problem, said a University of Illinois Extension horticulture educator.

“Hot, dry weather leads to high moisture deficiency in vegetable gardens,” said Maurice Ogutu. “Vegetables require adequate moisture supply throughout the growing season in order to sustain optimal growth for production of good, quality fruits, greens, tubers, or bulbs.

Photo of vegetable basket“Some vegetables can tolerate mild water stress without serious negative impact on yield during certain periods of their growth cycle. However, all vegetables have critical water need periods, and inadequate soil moisture during this period results in serious yield loss. Make sure vegetables get adequate moisture during this period.”

Ogutu noted that the critical water need period varies among different kinds of vegetables. He outlined some of the commonly grown vegetables and the stages when water is critical:

“With the critical growth stages in mind, these tips can help you achieve higher water use efficiency in your vegetable garden,” said Ogutu.

“Add plenty of compost or manure to your garden before planting to improve the water-holding capacity. Have a small garden that will not require a lot of water. Plant early so that Mother Nature can provide most of the garden’s water needs. Space vegetable seedlings so that the ground is well-covered in early summer; effective spacing will decrease water loss through evaporation.”

He added that it is important to water your vegetable garden once a week, when less than one inch of rainfall is received that week. Soak the soil thoroughly with six to eight inches of water to ensure that it is available in the root zone for uptake by the vegetables.

“Water in the morning so that the leaves dry during the day,” he said. “Early watering helps avoid foliar diseases. Do no water vegetables at mid-day because much of the water will be lost through evaporation. Avoid frequent, light watering and turning the sprinklers on for a whole day.”

If you are putting in a late-summer or fall garden, Ogutu recommended the following watering guidelines: