Question
Frequently, and especially during this cool and early on wet season in Chicago, my plants, grown from current lot Burpee seeds, are large and produce a preponderance of non- fruiting blossoms. This season includes acorn, carnival, patty pan and zucchini.  Even my cucumbers have suffered this fate. Why is this and what can I do to improve yield?
Thank you.

Answer
Hi Howard,
Thanx for your question.  I'm really not a vegetable expert but have grown a number of different cucurbits, melons, squash, etc.  If the season is particularly wet and cool as it has been in many parts of the upper Midwest, production of squash is going to fall except with those cucurbits that have been hybridized for short-season climates.  You need some heat and some sunlight but you're now at the end of summer and you may not have much time left.  The non-fruiting blossoms you speak of are generally the male blossoms as cucurbits have both male and female blooms on the same plant.  The female blooms will have a tiny squash or cucumber (the ovary) behind the flower while the males are more numerous and do not have such a growth.  Cucumbers especially decline in the hottest months of the summer and generally recover once temperatures decline to the 80s.  Yield sharply decreases when the nights drop into the 50s and day temps are hard pressed to exceed 75癋.  

In the future, what you might want to do is contact the Cook County Extension Office and ask for a list of cucurbit cultivars that are more successful in your climate.  The extension is a service of the University of Illinois and can be very helpful in this regard.  Here is a link.

http://web.extension.uiuc.edu/cook/

I hope this helps.
Tom