Will Bean Seeds Soaked in Hot Water Grow Faster?

Planting Beans

• Plant beans after all danger of frost passes in the spring. Because they are sensitive to cold temperatures, beans need warm, moist, well-drained soil to germinate. Beans grow shallow root systems, requiring frequent and careful cultivation. In moist soil or warm water, the seed coat softens and the inside of the bean swells. The root grows first, pushing through the seed coat. Once the leaves and stem push above the soil, the leaves will unfurl quickly. If sprouting seedlings in peat pots, soak the pots before planting them so that they break down quickly.

To Soak

• Seeds need oxygen to germinate, so they will not germinate while soaking underwater. The beans must be removed from water before planting. Iowa State University Extension and The National Gardening Association recommend soaking bean seeds, pointing out that bean seeds have a very hard seed coat. Soaking them, especially in warm water, softens that coat and allows the seed to germinate faster. Different types of beans soak different amounts of water. When soaking before planting, mix 1/3 beans to 2/3 water. You cannot use too much water because the beans will only absorb a certain amount. You can soak them too long, though. The water should be no more than 60 to 100 degrees Fahrenheit to avoid cooking the beans. Soak the bean seeds overnight, swishing them around periodically to make sure the beans are evenly wet. The seeds should be planted the next day, spaced 4 inches apart and 1-1/2 to 2 inches deep in rows 12 to 14 inches apart.

Or Not to Soak

• The University of Illinois Extension Service points out that seeds of most varieties of beans tend to crack and germinate poorly if the moisture level in the soil is too high. They recommend against presoaking. Instead University of Illinois and Walden University suggest planting beans without presoaking but only 1 inch deep in the soil. Follow with a thorough watering immediately afterward. Proper, well-drained soil will hold moisture without puddling and will stimulate germination. Another problem with soaking beans prior to sowing is that soaking encourages halo blight. Watch your seed beans for wrinkling, disfiguring or yellow spots that indicate potential disease caused by moisture in your seed beans. Throw away any infected bean seeds.

Decisions, Decisions

• Bean mosaic diseases turn bean plants yellowish green and stifle the production of bean pods. Mosaic diseases and blight are bacterial infections that usually appear on wet plants or water-soaked seed beans, pods, leaves and stems. It can be passed between wet plants or seeds on your hands. Selecting mosaic-resistant bean varieties and keeping the plants and seeds dry is the best way to deal with mosaic diseases. Ultimately, the decision you have to make is whether the need for speed in germination justifies the greater risk of bean plant diseases to your plants from presoaking the seeds.