Insufficient moisture during this time may result in small, seedy berries. Weed Control Weed control in raspberries is necessary to reduce competition for water, nutrients, and sunlight. Cultivation and mulches are the most practical control measures for home gardeners. Cultivate the raspberry planting frequently during the spring and summer months. Small weed seedlings are relatively easy to destroy.
Large weeds are more difficult .
To prevent injury to the roots of the raspberry plants, don't cultivate deeper than 2 to 3 inches. Mulches help to control weeds and conserve moisture. Possible mulching materials include straw, crushed corncobs, chopped cornstalks, sawdust, wood chips, lawn clippings, and shredded leaves. The depth of mulch needed depends upon the material used. The optimum depth ranges from 3 to 4 inches for fine materials, such as sawdust, to 8 to 10 inches for straw on well-drained soils.