How Much Water Do Grapevines Need?

About Growing Grapes

• Choose grapes that grow well in your area and for the purpose you intend. Not all cultivars can be used for hand-eating. Grapevines adapt to a wide variety of soil types, but dislike poor drainage that keeps their roots wet for long periods of time. Grapes available to gardeners are self-pollinating, so you do not have to rely on bees or hand pollination to spread the seeds. Normally, it take three years for grapevines to become established sufficiently to produce a crop, but once they are established, grapevines can produce fruit for up to 40 years, according to Ohio State University horticulturist Gary Gao.

Watering At Planting

• Before planting set the grapevines in a bucket of water to soak their root systems for two to three hours. Proper watering is essential during the first year after planting to establish a good root system for the vines. Grapevines require 1 inch of water each week throughout the first growing season, either by rainfall or irrigation, according to Iowa State University horticulturist Richard Jauron. Water plants thoroughly after setting into the ground, and then irrigate every seven to 10 days during dry periods.

Watering Mature Plants

• Water to a depth of 12 inches with each irrigation. Deep, infrequent watering is better than shallow, frequent waterings. To determine whether you need to irrigate, stick your finger in the soil to a depth of 1 or 2 inches. If it is dry at this depth, soak the soil deeply, according to the National Gardening Association. To determine how deeply the water is penetrating, poke a long metal rod into the ground. It will move freely through the soil until it hits dry ground.

Overwatering

• Monitor soil moisture carefully to avoid overwatering the grapevines. Grapes do not tolerate having their roots in soggy soil conditions. To improve soil texture, work in large amounts of compost or other organic matter thoroughly to the top 4 to 6 inches of soil. The organic matter will break up the soil, providing more spaces for air and water to penetrate. This helps not only in retaining water, but also in drainage of water throughout the root zone. Limit additional watering during periods of heavy rain.