According to Elsa Sanchez, Associate Professor of
Horticultural Systems Management at Penn State, University high
temperatures have been shown to reduce flower development and cause
abnormal growth and development of male and female flower tissues.
That can mean no fruit or small, misshapen fruit.
like it hot, hot hot!
tomatoes are most productive when daytime temperatures are in the 70
to 85 degree range and nighttime temperatures are between 59 and 68
degrees. Daytime temperatures above 90 degrees causes reduced
flowering and fruit set, as do nighttime temperatures above 70
degrees. Research indicates that high nighttime temperatures may be
more disruptive to pollen development than daytime heat.
Tomatoes are most productive when daytime
temperatures are in the 70 to 85 degree range and
nighttime temperatures are between 59 and 68 degrees
can also hamper pollination in tomatoes because the pollen remains
stuck to the anther (the male, pollen-producing part of a flower) or
clumps together in such a way that inhibits complete pollination.
Peppers and tomatoes are in the same family, and peppers react
pretty much the same way to high temperatures.
Cukes, Pumpkins & Squash
noted that cucurbits such as squash, cucumbers and pumpkins Ė
species that have separate male and female flowers on the same plant
- tend to produce all male flowers when temperatures are 90 degrees
or above. Male flowers provide pollen, but not fruit, so it is not
surprising that your squash yield is down as well.
cannot change the weather, there are some steps you can take to help
your vegetable garden through the heat. Provide an inch or two of
water a week, preferably in one or two long soaking sessions. The
idea is to wet the soil four to six inches deep to encourage the
plants to develop a deeper, more drought resistant root system.
Watering a little every day has the opposite effect: it encourages
plants to have shallow root systems that have little drought
It is also
important not to overwater during hot, dry weather. Stick a finger
two or three inches into the soil to feel the moisture level. If it
still feels damp, hold off watering another day; if it is dry, go
ahead and water. This rule of thumb applies to ornamentals as well
vegetable garden with three or four inches of clean oat straw helps
conserve soil moisture, moderate soil temperatures and helps keep
weeds down that would otherwise compete with the vegetables for
water and nutrients.
Now that the
weather has moderated, these crops should begin producing again. If
only the fruits get a chance to mature before the first frost!
Late blight on
Tomato Growing 101