How Much Should Bean Plants Be Watered?

Planting

• Plant bean seeds in dry soil without pre-soaking, as they have a tendency to crack if they are exposed to excess moisture at this stage. Once planted, water the seeds in so that the soil is just moist to the touch. Keep the soil slightly moist as the seeds germinate and begin to grow by watering gently every other day.

Young Transplants

• As the beans develop, you will need to water them more thoroughly. A bean plant's roots are generally shallow and only take water from the top foot of soil. Water the plants to this depth, then allow the surface of the soil to dry out and the plants to start showing signs of needing additional water (slight wilting during hot weather) before watering thoroughly again. This method is more beneficial to beans than frequent, shallow watering as it encourages deeper root growth to provide more support for the growing plant.

Flowering and Setting Fruit

• For bean plants, the most critical stage for providing adequate water is during flowering, as this period will determine how much fruit the plant will set. Beans have some resistance to drought at this stage, so you may get away with a few dry periods, but provide water regularly to avoid blossom drop and low yields. In general, beans use a minimum of a 1/4 inch of water each day during flowering and should therefore need a thorough watering (to a depth of at least 1 foot) every five to seven days in hot weather.

Symptoms of Over and Under-Watering

• Healthy bean plants are a bright, dark green color with dense foliage. Plants with slightly wilted, grayish leaves are showing the first signs of drought and should be watered to prevent blossom drop. Bean plants are particularly at risk of this during hot, windy periods. Slow-growing plants with brown-tipped leaves are showing signs of over-watering, which clogs up the soil and prevents oxygen from reaching the roots. It is important to hold off watering again until the top 2 inches of soil is dry so that the plant has chance to recover.