How Often Should You Water New Blackberries?

Irrigation Method

• The irrigation method affects how often blackberries require water. Standard overhead irrigation, either by hand or with sprinklers, requires more water than do trickle and drip systems. Overhead watering results in more water loss to evaporation and less water soaking into the soil reaching the blackberry roots. Trickle systems deliver water directly to the soil, so that the moisture seeps down to the roots before it can evaporate. Trickle systems allow you to water more deeply, less often and with less water than do overhead systems.

Watering Frequency

• Blackberries require 1 to 1 ½ inches of water per week for most of the year. This amount is the same for both newly planted and established bushes, but newly planted bushes are more prone to drought damage, so it's important not to miss a watering. Irrigate one to two times weekly using a trickle systems, or every two to three days with overhead irrigation. The soil should remain moist but not soggy or muddy. Standing water around the plants and in the soil leads to root rot and plant decline. Blackberries have increased water needs when the begin forming fruit and require up to 2 gallons of water per plant per day regardless of the irrigation system used.

Conserving Moisture

• Practicing water conservation techniques helps minimize the need for frequent irrigation. Mulch around the plants immediately after planting with a 4-inch layer of straw. The mulch inhibits rapid moisture evaporation from the soil. Mulch also minimizes weed competition with the young blackberries. Weeds rob moisture and nutrients from the soil. Install trickle irrigation systems under the mulch, so that the water doesn't evaporate out of the upper mulch layers as soon as it is delivered.

Soil Considerations

• Good soil prevents water stress to the new blackberries. Quality soil drains quickly enough so the soil never becomes soggy, but retains enough moisture to prevent drought stress. Planting the new blackberries in an area with a sandy loam provides good drainage and moisture retention. Choosing a bed with a high amount of organic matter, or working in a large quantity of compost or peat before planting, helps minimize the need for frequent irrigation. The blackberries still require regular watering the first summer after planting in an organic-rich soil, but in future years, they typically survive with only periodic irrigation during extended dry periods and during fruiting.