How to Grow Abundant Squash (and the surprising thing that might be keeping you from it)

When You Know There’s a Problem

For many years when I planted vegetables, if they did well I was happy, and if they didn’t do well…well, I didn’t always know the cause. This is tough, because how do you learn from failure if you’re not sure what caused it?

This was particularly true with squash, zucchini and cucumber—all three members of the cucurbit family. Often the plants would get enormous, with enormous flowers, and it would look like small squash or cukes were beginning to grow…and then they didn’t. They would shrivel, brown, and fall off. What happened?

Although cucurbits have many nemeses: squash bugs, cabbage loopers, aphids and powdery mildew for starters—what does it mean if your tiny squash die off when you’re not (amazingly) dealing with any of these pests? Mysteries in the garden can really throw you for a loop, if you don’t have clarity.

It’s All About Reproduction

It took me awhile to understand that often this was happening not because of poor soil, lack of (or too much) water, fungus or insects—it was happening in a whole different arena—reproduction.

A plant’s goal is always to produce seeds. It’s here to continue to be here. So the process of getting to that final goal starts, of course, with pollination: that first, critical step of a mature flowering plant’s life cycle. After all, if there’s no pollination, there’s no seeds (or the vegetable around them which we eat.) But for a long while I was confused:  there seemed to be tiny squash already growing beneath some of the flowers: didn’t that mean the squash flower had already been pollinated?

Every morning when you look at a squash plant, you’ll see its huge—and quite beautiful—orange flowers. (Squash flowers close up at night.) But these flowers are not all the same: some are male, and some are female. Cucurbits are self-pollinating: that means that both flowers exist on the same plant. Pollination occurs when pollen from the male flower’s anther gets onto the female flower’s stigma.

How You Tell Female and Male Squash Flowers Apart

Plants in the cucurbit family have many more male flowers than female. So most of those initial flowers you’re seeing in the morning are male. How to know for sure? Male flowers are on the end of long, thin stems, and their exposed anther is fairly long and thin, and comes to a point.  Female squash flowers, on the other hand, have a bulbous circular center area that will almost look like another small flower. And, instead of lying at the end of thin stems, they are attached to much thicker stems that look like tiny, forming squash. Aha! So that’s why I thought the flowers had already been pollinated, and why the fact there was already squash was so confusing.  The reality was that these squash weren’t the result of a pollinated flower—they were instead simply the signpost that this was a female flower.

When Nature Doesn’t Do Its Thing

Once I learned this very important distinction, I started to look at my squash plants differently. Often those “mini squash” attached to the female flowers would shrivel and dry up, as would the flower. What looked promising instead looked oh so sad. And it was kind of sad, because natural pollination hadn’t occurred: the female flower had not been pollinated by the male, so its life cycle had been abruptly cut short. Both flower and mini-squash simply…died.

Pollinating by Hand

The vast majority of the time, nature’s flying and crawling pollinators do exactly what they do best: they get that pollen from the male to the female. But, as was the case with my squash, sometimes they don’t. And that’s when your squash need your help. The process of pollinating the female flowers couldn’t be easier: using your finger or a cotton swab or the like, rub the anther of the male flower to remove some pollen (I’ve found wetting my finger first works best, so that it sticks.) Then take the pollen over to the female flower, and deposit the pollen onto its pistil.  The trickiest thing I’ve found, is getting at the female flowers when they’re fully open. Often they’re not. So if that’s the case, you can (ever so gently) tease open the partly-closed female flower, exposing the pistil, deposit the pollen, and let it close up again.

Continue to do so as more female flowers emerge. With this bit of extra help, coupled with your other job of keeping harmful insects at bay, your squash, zucchini and cucumber have every chance of producing a large and healthy crop.