Can You Spray Weed Killer Around Blackberries?

Selective and Non-Selective Herbicides

• Selective herbicides are formulated to eliminate specific weed types and will not injure blackberry crops. Accurate weed identification, proper timing and chemical concentrations are crucial. On the other hand, non-selective herbicides are designed to injure or kill all plants that it contacts. These chemicals are most often used to destroy emerged, perennial weeds before planting blackberry plants. Non-selective herbicides will eliminate a wide variety of weeds, but they can also harm blackberry plants. Use only selective herbicides while blackberry plants are present.

Timing

• Once blackberries are planted, perennial weeds are both difficult and expensive to control. It is therefore most cost-effective to eliminate as many weeds as possible before planting. Within commercial operations, blackberry fields are treated with a non-selective, systematic herbicide many weeks before planting, which typically occurs during the spring. After planting, fields are treated with a pre-emergence herbicide. This treatment is repeated during the fall. Established plantings also receive spring and fall pre-emergence herbicide applications.

Weed Management Need

• Uncontrolled weed growth will negatively impact blackberry growth in several ways. The presence of weeds and the increased competition they present can limit blackberry plant growth during the establishment years and lower fruit yields during production years. Too many weeds will reduce air movement through shrubs, which will leave higher moisture levels. These conditions are known to favor and exacerbate disease within crops.

Considerations

• Weeds can be very difficult to control once they become established among blackberries. Chemical weed treatments can be very effective treating this problem, but they can injure or harm plants if they are not applied correctly. While herbicides are a necessary part of weed control in most commercial growing operations, it should be used much more sparingly, if at all, by home growers. A strong reliance on one type of herbicide can result in the eventual dominance of a non-treated weed species.