Butternut pumpkins not growing

Question

Hi,
My butternut pumpkin vine is growing vigorously but when I get little pumpkins, they don’t continue growing and die off. I am feeding with a soluble fertilizer and watering regularly. They are being pollinated because the pumpkins would not appear… am I right? What is going wrong?

Answer 1

The small pumpkins will always be at the bottom of a female flower, regardless of pollination. These are the ovary of the plant. Once pollinated, they will swell.

There could be a few things happening. Your fertilizer could contain too much nitrogen. This is usually heavy in slow release fertilizers. This nitrogen release will inhibit flowering and prevent the uptake of potassium and phosphorus.

Feeding with a fertilizer high in potassium and phosphorus will likely correct the issue, but there could be something else as well.

Magnesium and calcium can be deficient in the soil. You can safely increase the amounts of these by adding DOLOMITIC lime. It is abundant here in the US, and very natural, containing only calcium carbonate, and magnesium carbonate.

Stay away from hydrated lime, since it is only calcium hydroxide, which is caustic, and lack magnesium, which is needed for the uptake of calcium.

If you can post photos, then it would give me a better idea of what is going on. Then I can recommend the best treatment option for your situation.

This article will give you more information: https://www.gardeningknowhow.com/edible/vegetables/squash/growing-butternut-squash.htm