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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Gardening: When high heat keeps honey bees away, gardeners can help

An old electric toothbrush can be used to vibrate pollen loose to help speed up fruit set on tomatoes.  (Pat Munts/For The Spokesman-Review)
By Pat Munts For The Spokesman-Review

It is the middle of August already.

You wouldn’t know it if you were using ripe tomatoes or zucchini as a marker, though. Both of these crops are late this year.

You can blame it on our cool, wet spring and early summer. Temperatures barely got into the 70s in June which slowed the initial growth of most warm season crops. My tomato plants are usually over 2 feet tall when I pull off the row cover at the end of June. This year, they were only a scrawny 18 inches tall. The zucchini squash just sat there until the middle of July all because of the cool weather.

The challenge is that under normal conditions we have a short window of warm days and nights between mid-July and mid-August that the plants must be flowering during that time or we aren’t going to get anything. If we do, it is going to be very late. Late enough that we might be bumping up against an early sneaker frost.

With the warm and almost too hot weather we’ve had over the past several weeks, the plants have taken off and are finally producing flowers. I say too hot because temperature over 90 degrees aren’t conducive for pollination. The bees are home keeping their hives cool and the pollen dries out too much to stick to the female part of the flower. The solution to the challenge is for you, the gardener, to do a little good, old-fashioned matchmaking and help with the pollination.

Let’s start with the zucchini squash. These plants have male and female flowers on the same plant. The female flowers are closer to the center of the plant and have a bulge at the base of the flower while the male flowers are taller and have no bulge. The male flowers come out a few weeks before the female flowers.

Once both flowers are open, the bees move pollen from the male to the female flower. If there is no pollination, the female flowers might put out a short, small fruit that withers. To help with pollination, take a cotton swab tip or a small artist’s brush and rub pollen from the male flower onto the center of the female flower. You may need to do this several times over a couple of weeks.

Tomato flowers, on the other hand, produce their own pollen that is moved around by bees and other pollinators to form new fruits. A tomato plant usually sets fruit from the bottom of the plant upward. If the pollinators are busy with other activities in the hot weather, you can help them along. Get an old electric toothbrush and set it next to a flower and turn it on. The vibrating brush head will cause pollen to fly far enough to hit other flowers.

To help ripen fruit once our nights cool into the 40s, cover the plants with floating row cover to hold in heat and protect from frost.