Nothing compares to the taste of fresh, ripe strawberries bursting with juicy sweetness. Many home gardeners enjoy the convenience of having this taste treat growing right in their own backyard. However, bountiful strawberry harvests require diligent plant management, and even healthy plants can experience unexpected problems with diseases and pests.
White grubs, strawberry root weevils, strawberry rootworms and sting nematodes can significantly damage strawberry roots. The white grub and the strawberry root weevil lay eggs in the soil near strawberry plants and the strawberry rootworm lays eggs in leaves near the ground. The newly hatched larvae of all three of these pests feed on the strawberry plant roots. Sting nematodes are roundworms that attack the root tips of strawberry plants, preventing new root growth. All of these pests are capable of killing strawberry plants.
The strawberry rootworm larvae attack the plant's roots, but the adult strawberry rootworm is a leaf-eating beetle that may even attack the fruit when the foliage can no longer support its growing population. The leafroller, a reddish-brown moth with yellow markings, lays its eggs on the leaves of strawberry plants. The larvae then feed on the outer layer of the leaves, secreting silken threads as they eat, which fold and tie the leaves together. The two-spotted spider mite feeds on plant sap, causing leave to appear mottled or speckled. The leaves then die and drop.
Fruit and Flower Pests
Common pests that attack the fruit and flowers of strawberry plants are strawberry clippers, tarnished plant bugs, strawberry sap beetles and slugs. Slugs and strawberry sap beetles feed on the berries, leaving gaping holes in the fruit. The strawberry sap beetles then lay eggs in the holes and the new larvae also feed on the fruit. Strawberry clippers and tarnished plant bugs attack the strawberry blossoms. The strawberry clipper lays a single egg in the bud and then secures the bud closed. The hatching larva then feeds on the bud for three to four weeks. Tarnished plant bugs feed on the sap of the flowers.
Strawberries are susceptible to a variety of diseases. Powdery mildew, leaf spots and slime mould can attack strawberry plant foliage, but do not usually affect fruit production. Grey mould, Rhizopus rot and leather rot attack the berries, causing discolouration and turning the fruit inedible. The roots of the strawberry plants are susceptible to black root rot and red stele. Black root rot is caused by root-attacking fungi. Red stele is a fungus that causes the tips of the roots and lateral roots to die and decay, stunting the growth and production of the plant.
To manage these pests and diseases, begin by planting disease-resistant varieties. Planting in soil that drains well will help prevent root diseases. Regularly removing damaged fruit will help keep fruit-eating pest populations down. Regular removal of damaged leaves and using fungicides formulated to be safe for strawberries and sulphur sprays will control foliage fungi like powdery mildew. Most insect pests can be controlled with regular applications of neem oil-based sprays.
- University of Illinois Extension, Strawberries and More: Insects and Diseases
- University of Florida IFAS Extension; Nematode Management in Strawberries; J. W. Noling; December 2009
- University of Minnesota Extension; Strawberry Diseases; Ward Stienstra; 1998
- Colorado State University; Strawberry Diseases; C.E. Swift; April 2008
- University of Florida IFAS Extension; Growing Strawberries in the Florida Home Garden; Craig K. Chandler, et al.; December 2008
- North Carolina State University Extension; Strawberries in the Home Garden; E. Barclay Poling; September 1993