Garden News: Better pollination prevents disfigured squash

Many home gardeners and commercial producers have been reporting disfigured squash fruit this spring, says LSU AgCenter horticulturist Kiki Fontenot.

Squash is a monocot, which means it produces both male and female flowers on the same plant. Only female flowers produce fruit, but both types of flowers are needed for cross-pollination and fruit production.

Flowers will fall or fruit will be disfigured if the flower is not fully pollinated, she says.

“Bees are active in flowering shrubs, such as privet and ligustrum, right now and not as active in our vegetable crops,” Fontenot says.

She suggests several ways to improve pollination, including:

Try planting flowers near your vegetable garden to attract pollinators.

Encourage bees by reducing insecticide use in your yard.

Use a tiny paintbrush to pollinate flowers by hand.

If your squash vines are not producing flowers but the plants are large and healthy looking, you have probably overfertilized. The remedy is to quit applying fertilizer and remain patient because you have delayed blooming.

If you are getting flowers but they are falling off, it’s because some of them are male.

The male flowers usually appear first followed by a mixed production of both female and male flowers. Male flowers will not produce fruit and always fall. Female flowers have a bulge right behind the flower on the stem. That’s what will become a fruit.

Another explanation for falling flowers is that the pollen may be damaged by insects feeding on the flowers. Inspect flowers for tiny insects and treat them accordingly, Fontenot says. Once you correctly identify the insect, find an insecticide that’s labeled for both the insect and the crop and use the labelled rate.

Only use pesticides very early in the morning or at dusk when bee activity is reduced.

Got a gardening question? Write to GardenNews@agcenter.lsu.edu.