Blackberries - Ask Extension
Can you tell me what is going on with my blackberries? This happens every year and I get very few berries that are decent enough to eat. I cover the t...
Knowledgebase
Blackberries #909901
Asked July 15, 2025, 10:07 AM EDT
Can you tell me what is going on with my blackberries? This happens every year and I get very few berries that are decent enough to eat. I cover the top of the plants with garden fabric before they start to ripen so it's not sunscald.
Washington County Maryland
Expert Response
Hi- sorry to hear about your blackberry issue. The symptoms are consistent with both sunscald and spotted wing drosphila (SWD) feeding injury.
Sunscald-30% shade cloth will help protect the fruit from sunscald. If the garden fabric you used is row cover material it can increase the temperature around your plants increasing sunscald risks.
SWD- we suggest you place 25-50 affected fruits in a container. Mix 2 TBS of salt with a pint of water and poor it into the container. Wait 15 minutes and look for signs of SWD larvae floating in the water.
Resources on SWD:
https://extension.umn.edu/yard-and-garden-insects/spotted-wing-drosophila#using-insecticides-992612
https://fff.hort.purdue.edu/article/monitoring-spotted-wing-drosophila-swd-in-small-fruits/
Jon
Sunscald-30% shade cloth will help protect the fruit from sunscald. If the garden fabric you used is row cover material it can increase the temperature around your plants increasing sunscald risks.
SWD- we suggest you place 25-50 affected fruits in a container. Mix 2 TBS of salt with a pint of water and poor it into the container. Wait 15 minutes and look for signs of SWD larvae floating in the water.
Resources on SWD:
https://extension.umn.edu/yard-and-garden-insects/spotted-wing-drosophila#using-insecticides-992612
https://fff.hort.purdue.edu/article/monitoring-spotted-wing-drosophila-swd-in-small-fruits/
Jon
