Late blight is becoming a threat to tomato growers again this year as the pathogen is being spotted in several locations across Pennsylvania, New Jersey and Connecticut. In 2009, the pathogen spread through the Northeast and mid-Atlantic, wiping out tomato and potato crops.
Although mostly commercial production fields have been hit, greenhouses and home gardeners should be vigilant as well.
The recent warm weather has been helping to slow the spread since the disease does best in cool, wet conditions in the high 60s. But warm weather will not kill late blight, only stop it from infecting other plants as quickly.
Growers should be on the lookout for brown spots on fruit and fuzzy growth on the underside of leaves. Other signs are pale green leaves, and long brown lesions on the stems.
To prevent late blight, growers can apply protectant fungicides, or, for organic growers, copper products can be used.
Latest from Garden Center
- Jackson & Perkins expands into Canadian market
- Green & Growin’ 26 brings together North Carolina’s green industry for education, connection and growth
- Cincinnati Zoo & Botanical Garden debuting new perennial section at 2026 Breeder Showcase
- The Garden Conservancy hosting Open Days 2026
- Registration open for 2026 Perennial Plant Association National Symposium
- Monrovia's Bee a Winner program enrollment deadline approaching
- Fred C. Gloeckner Foundation Research Fund calls for 2026 research proposals
- [WATCH] The Cloud Makers inventor on how she made it rain at TPIE 2026