‘Cushy’ conditions not ideal for squash

QIn the past few growing seasons, our zucchini, winter squash and pumpkins have grown wonderfully large and healthy, but they have produced mainly male flowers and therefore few fruits. Can you explain this? We don’t want to repeat this disappointing pattern.

A: It’s usual for some kinds of squash to produce only male flowers at the start of the season. This is nature’s way of ensuring there is an abundance of pollen around when the females show up.

As the season advances and the weather settles into warmth, many flowers of both types will usually appear, especially if the site is sunny with a modestly moist, well-drained soil that’s balanced in fertility.

You describe your plants as big and healthy. That suggests a possible cause of the problem.

Conditions that are over cushy, with too much soil moisture and richness, have been known to keep plants lolling about in pollen-producing mode. An excess of nitrogen in the soil is a common issue, as is a lack of sunlight.

Stresses to the plants, such as an over-dry soil, can sometimes induce the same problem.

In planning for this year’s plantings of zucchini, winter squash and pumpkins, make sure the site is in full or nearly full sun. Lime the soil if it’s strongly acidic. A slightly acidic to neutral pH is fine.

Avoid overloading the planting area with nitrogen-rich manures and composts, and supply the soil with phosphorus (bone meal, rock phosphate) and potassium (kelp meal, greensand) to balance nitrogen.

Consider grouping the plants together. Once you do get both male and female flowers on the plants, a fair-sized grouping of them gives good numbers of both male and female flowers open at the same time, in the same place, to attract bees.

You may want to try a few different varieties, too.