Expert: C.L. Fornari - 7/11/2007

Question
Mr. Fornari,
I live in eastern Virginia and have been gardening for a few years. Every year I have planted zuchinni and they do wonderful for the first 60 days or so. I get to harvest some fuits of may labor. Then I notice the budding flowers  being cut off at the stem and the stems near the ground turn a mushy tan color and the plant starts dying off.I cut one of the dead stems in half and found little bores or catipillars inside the stem. I have used garden spray to keep the bugs and catipillars off since the day they were planted. This happens every year can you help me prevent this happening in the future.

Thank you,
David

Answer
David,
Sounds like you have the squash vine borer - the enemy of gardeners through out the country!  The adult - which looks like a wasp but is actually a moth - lays eggs on the stem and the eggs hatch into larvae that tunnel into the stem and eat so that the stem wilts and dies.  You can cover the stems (but not the flowers) with floating row cover or foil...some people even squirt shaving cream over the stems every few days to preven the egg laying.

Other methods abound:
http://tomclothier.hort.net/page30.html
or
http://www.gardening-tips-perennials.com/Doug_Greens_Garden-squashborer.html

Sometimes a combination of tactics works: sow seeds every three weeks, use cover or shaving foam, plant some sold stem types (seeds of italy) and plant every three weeks.

Know too that some years are worse than others = I had borers for three or four years, but haven't been troubled by them for the last 10 years.

all the best,
C.L

C