Gooseberries appear very robust thanks to their thorns. Nevertheless, some diseases and pests give them a hard time.
While gooseberries have thorns that give them some protection, they are no less susceptible to fungal diseases and pests than other plants. On the contrary, because gooseberries are particularly susceptible to powdery mildew.
The yellow gooseberry wasp, American gooseberry powdery mildew and leaf fall disease are among the biggest threats to gooseberry bushes in your garden. We will explain how you can recognize the respective infestation and what preventive and control measures you can take to protect the plants and fruits.
Possible diseases and pests at a glance
Yellow gooseberry sawfly
» Detect:
The larvae of the yellow gooseberry sawfly eat the leaves of the berry bush. Severe infestation without resolute control often leads to complete defoliation, which also spreads to the fruit. Typically, the damage begins on the inner shoots of the shrub, and then gradually spreads to the outer area. You can easily recognize the larvae by their green-yellow bodies covered with black dots.
» Fight:
The most important preventive measure is loose, open pruning of the bush, which is also good for berry growth. Check the inner shoots regularly. As soon as you see the white, elongated gooseberry sawfly eggs, collect them thoroughly. Shake the bush vigorously. Overlooked larvae then fall off. Unfortunately, an advanced infestation can only be effectively combated with insecticides. Since the larvae of the yellow gooseberry sawfly overwinter in the ground, it makes sense to replace the soil under the shrub next year for protection.
Leaf Fall Disease
» Detect:
If you discover yellowish spots on the leaves of the berry bush during rainy weather in the summer months, this is an indication of leaf fall disease. The dots soon darken in color and expand into patches that eventually merge. ThatLeaf yellows and falls off during summer. The shrub does not die immediately, but is extremely weakened.
» Fight
Leaf disease is caused by the harmful fungus Drepanopeziza ribis, which overwinters in gooseberry leaves. The complete removal of all leaves is the first and most important control measure. Also, thin out the shrub heavily before next year's growing season to ensure good ventilation of the leaves.
» Tip: Neither the leaves nor the green waste should be put on the compost, otherwise the fungus can spread further.
American Gooseberry Powdery Mildew
» Detect:
An infestation with American gooseberry powdery mildew can be recognized by a dirty-whitish discoloration of the shoot tips, the leaves and the fruit. Unfortunately, the disease cannot be completely ruled out, even in varieties that are commercially labeled as resistant to powdery mildew.
» Fight:
Remove all affected parts of the plant as soon as you notice an infestation. Before the start of the next growing season, trim shoots that will not fall victim to annual pruning anyway by a third. The fungus prefers to overwinter in the shoot tips of the bushes.