How to Prevent Mold on Raspberry Bushes

Water the raspberry plants only when the top of the soil feels dry. Overwatering is one of the biggest causes of mold development. Direct water only at the soil under the bush---not at the leaves. Wet foliage encourages the development of mold.

Rake up all dead leaves, mulch and broken stems from underneath the raspberry bushes in the early spring and dispose of them in a trash bag. This material often harbors mold spores that can infect the bushes once temperatures warm.

Prune back all overhanging vegetation, such as tree limbs and large shrubs, using loppers or a pruning saw, to allow more penetration of sunlight. Full sunlight exposure helps prevent the development of mold and increases fruit production.

Spray all of the canes and leaves with a preventive fungicide that targets mold or mildew. Do this after all the bush's flowers have fallen but before fruit set.

Wait until after the raspberry bush stops producing fruit and then prune off all dead stems near the base of the plant to prevent them from harboring mold. Then prune off one-third of the tallest green stalks near the ground to improve air flow in the plant. Remove the canes at different areas of the bush so as not to create unsightly gaps.