One last gasp for summer vegetables

To pull or not to pull? That’s the question after high temperatures just about finished off our summer crops.

Sacramento started September with a string of triple-digit days. On Friday (Sept. 6), the Sacramento region remained under a heat advisory until 8 p.m. So far this month, daytime highs averaged just under 96 degrees – almost five degrees above normal for this week.

This heat browned leaves and vines on many plants. It also brought bee activity (so crucial for pollination) to a standstill. And that impacted squash.

In this weather, zucchini develop little baby squash that start out OK, but never seem to develop. It rots before it reaches 4 or 5 inches long. The Brits call it “courgette rot,” referring to the English name for zucchini. It’s due to insufficient pollination.

Extreme heat complicates bees’ lives. If temperatures top 100 degrees (as it has almost daily this month), worker bees need to bring water back to their hives, from one quart to a gallon a day. They’re too busy to pollinate.

So, female zucchini blossoms – which start forming baby squash before the bees arrive – never get the attention they need from pollinators. Without proper pollination, the squash rot before they mature. This issue can happen to other cucurbits as well such as crookneck squash and pumpkins.

Tomatoes depend on wind, not bees, for pollination. But on days above 95 degrees, tomato pollen dries out before it ever has a chance to set fruit.

I’ve been nursing my vines along in hopes of fall tomatoes. Our red-hot July (the hottest July on record in Sacramento) prevented fruit set during a time when tomatoes are usually at their most productive. We had just enough of a break in the weather in August for my tomatoes to set some fruit; those baby green tomatoes are forming now. But will they have enough time to mature?

Although these hot days feel like midsummer, chilly fall weather is not far away. Those baby toms need at least six to eight more weeks of warmth – just not all this heat.

That leads back to the original question: To pull or not to pull? The plants with baby tomatoes or squash – or flowers – can stay put for a little longer. Even if those green tomatoes never turn red on the vine, they may still ripen indoors on the kitchen counter.

Trim off dead or browned leaves and vines, so plants can concentrate on wrapping up their production. Give the bushes a deep watering and some fertilizer high in phosphates such as bone meal. (Hope springs eternal.)

Otherwise, turn the page – and pull out those faded summer crops. Remember: September is an excellent time to plant cool-season vegetables.