The prolonged hot, dry weather pattern has created some vegetable gardening challenges. Garden plants (and all other kinds of plants) respond to the weather conditions by adjusting vegetative (foliage) and reproductive (fruiting) growth.
Vegetable plants respond to environmental conditions. When it is too hot for us, we go inside to the air conditioning or move into a shady spot in the yard. Our vegetables are out there in the full sun. So if it is too hot and dry, tomatoes and peppers will abort any unopened flowers until better weather conditions return.
This protects the plant from attempting to fulfill a fruit when water is lacking and maintaining itself under better conditions.
Now that our vegetables are moving from the general growth stage to producing flowers, fruits and seed pods, a consistent level of soil moisture is critical for health and for harvesting high-quality, nutritious fruits and pods. Cucumbers, for example, will go from a pollinated flower to a harvestable fruit in about a seven-day period. If soil moisture is lacking at any point, you find yourself with cucumbers that appear normal on one end and taper down on the other and can be bitter tasting. If you’re going for a larger, longer cucumber, the fruit may appear “fat-skinny-fat as the available water has changed. Snap bean pods will have a similar reaction to a lack of available soil moisture. We expect a nice, full bean about 4 to 6 inches long with seeds inside just pushing at the bean pod wall. What we get is like those cucumbers. While not a fruiting vegetable, our lettuces will not be able to grow as rapidly as expected and the lettuce leaves will not have that expected tenderness.
Another vegetable that can disappoint us during hot dry weather are the onions, especially if growing bulb onions. If at any time during bulb growth and expansion, the onion does not receive enough water, bulb growth stops at that point. Even if we water or it rains, the bulb with not continue with expansion.
So we are not disappointed in the productivity of our vegetable gardens, here is a list of critical dry periods for some of our favorite vegetables:
Crucifers: head development
Sweet corn: silking, tasseling and ear fill
Cucurbits: fruit development
Tomatoes and peppers: fruit development
Beans: flowering through pod fill
For some of your vegetables, like the cabbage family and sweet corn, you only have one chance to get something worth harvesting and eating. Others, such as cucumbers, melons, squash, beans, tomatoes and peppers, will hesitate until better growing conditions return, but you do get harvestable produce at other times.
Have more questions? Contact your local Master Gardener Help Desk. In DuPage, Kane and Kendall counties, learn more at http://go.illinois.edu/HelpDeskMGdkk.
• Richard Hentschel is a Horticulture Extension Educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. This column originates on his blog at http://go.illinois.edu/overthegardenfence. To get more tips from Hentschel, watch his “This Week in the Garden” videos on Facebook and YouTube.