Pre-Emergent Herbicides for Raspberries

When to Apply Pre-Emergent Herbicides for Raspberries

• Pre-emergent herbicides specially formulated for raspberry plants are required to be applied to the soil bed before the weeds begins to grow and attack the plant. Timing is very critical when applying these herbicides. The best time to apply is two to three weeks before the weeds emerged in the past year. If applied too early, the herbicide may dilute and will be ineffective, leading to weed growth.

Effective Use of Pre-Emergent Herbicides for Raspberries

• Selecting the right pre-emergent herbicide can be a daunting task if one does not know what to look out for. When it comes to purchasing the most effective weed control product for your raspberry plants, it is important to check product reviews.

  Some commonly found pre-emergent herbicides are Diuron (sold as Karmex and Direx), Simazine (sold as Princep) and Oryzalin (sold as Surflan). Other pre-emergent herbicides for raspberries are Napropamide (sold as Devrinol), Norflurazonsold (sold as Solicam), Terbacil (sold as Sinbar) and Dichlobenil (sold as Casoron).

  Diuron an Simazine are both single-application herbicides that are applied during winter. Sometimes, two applications might be necessary, during spring and fall. Diuron has medium potential to leach and the EPA toxicity range is Class 3, while Simazine has large potential to leach, low water solubility and absorbs weakly but persistently into the soil. The EPA range is Class 4. Oryzalin can be applied to the raspberry plant during fall. However, sometimes an early spring application might be necessary to combat heavy weed growth. Oryzalin has small potential to leach and does not absorb strongly into soil. It is soluble in water and has an EPA toxic range of Class 4.

Applying the Pre-Emergent Herbicide

• Pre-emergent herbicides are available in granule spreader and spray bottle. When using the spray bottle, target precise areas that were attacked by weeds the previous year. When using the granule spreader, spread the herbicide granules around the soil bed using a spreader. Often, these granules are mixed with fertilizer that makes the application more effective. Simply, disperse the granules, turn on the hose to water the soil bed to activate the herbicide.

Understanding Herbicide Labels

• It is also advisable to read packaging labels to check the toxicity ratings given by the Environmental Protection Agency. The rating range is from Class 1 to Class 4. For raspberries, the recommended range is Class 3 and Class 4. The Class 3 label reads that the herbicide may be harmful if absorbed by the skin, inhaled or swallowed while Class 4 label would read non-toxic.