Friday, May 22, 2009

Frost and Chill Injury

Blackberry Winter is the term old timers call the period of cold weather that typically occurs when blackberries are in full bloom. This year the cold settled in several places in Western NC with temperatures as low as 27 in a few valleys and mid 30s in many areas. We had reports of light frost but not "killing frosts". However, the chill caused some damage to a lot of tender vegetation, particularly our in vegetable gardens. We continue to get calls regarding small yellow or necrotic (dead) spots on garden plants from Ageratum to Zinnias. Mostly on things like corn, tomato, pepper, and bean plants. Most of the plants will grow out of the damage, but remember damaged cells can be ideal incubator sites for pathogens such as botrytis, which could spread to other parts of the plant. If you notice damage on your plants or get calls from customers experiencing damage, monitor the issue and use preventative fungicides to keep pathogens in check. While most plants will grow out of the chill injury, expect delays in harvest time.

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.