[OregonYeti]

Why would a huge pumpkin plant abort all but one pumpkin?

This year when I prepared soil for two garden patches, in one of them a pumpkin plant came up, and I didn't plant any pumpkin seeds. It must have come from seeds that my teen stepson planted last year, that never turned into plants. Maybe he doesn't have a green thumb.

This plant got big. It covers an area about 15' by 10' right now. There have been a lot of flowers on it, but only one turned into a pumpkin (which by the way grew from unnoticeable to about a foot in diameter in about a week). The one successful pumpkin is now about 18" in diameter and is just barely starting to turn orange and will probably be ready for Halloween. That's really cool and my stepson is really happy about it. But the rest of them just started as little shriveled things and died.

This is kind of weird to me. Why would one grow so fast and nicely and the rest not?

[OregonYeti]

Maybe this is a mutant plant.

[KYHeirloomer]

Pumpkins do send out rampant vines, OY, which is why they're traditionally thought of as field crops rather than garden crops.

The real question is why did you got the one, not why only one.

Although selfing (i.e., a male on the plant fertilizing a female on the same plant) does occur with curcubits, they more often act as out-breeders; that is, males fertilize females on other plants.

So, one explanation is that you were just lucky.

Another possiblity: Due to environmental conditions it's possible that you've only been producing male flowers. I had that happen with zucchini, this year, for instance. Three plants only put out male blooms all summer, until just a couple of days ago when the first female showed up. So that, too, is a possibility.

Have you been monitoring the vine with that viewpoint?

A third possibility is insect activity or the lack thereof. Insects, primarily bees, are the pollination medium for cucurbits. If you're insect activity was low, for whatever reason, then the females just weren't getting fertilized.

Have you noticed females aborting? Lack of insect activity would explain it.

Yet another possibility is over-fertilization, particularly with nitrogen. This would cause the plant to grow heavily on foliage, and low on fruiting.

[allie]

Thanks for this information.

For the past two years, I get volunteer pumpkins where I toss vegetable scraps during the summer and fall. This is a brush pile across the drive from my home, as the landlord won't allow me to have a compost pile. Anyway, I get a plant in the late spring. It always has lots of blooms but will only have 2-3 pumpkins on it. They are the large pumpkins, like for carving. I water and fertilize them all summer. Just sharing as I never get any of the pumpkins but that's because people take them, not because of plant issues. I had one that was probably two feet in diameter and just turning orange and it disappeared. This is the second year in a row!

Anyway, the information above will be helpful if I attempt to grow pumpkins next year. Those will be planted closer to my house!

[KYHeirloomer]

That, sadly, is a common problem Allie. If fruits and vegetables are visible, and accessible, they disappear. Every passerby seems to think they are free for the taking.

With pumpkins it's even worse, because kids believe they are entitled to them no matter where they are growing.

Not a new problem by any means. In his memoir, Pioneer Life In Kentucke 1785-1800, Daniel Drake talks about growing the vegetable patch inside a corn field, so the ripening veggies would not be visible to passersby.

[KYHeirloomer]

Allie, if you do decide to plant pumpkins intentionally, treat them like any other squash; except leave lots of room.

In each "hill" put 5-7 seeds. After they germinate, thin to the strongest three plants.

Ideally, hills should be about 4 feet apart.

As I mentioned, pumpkin vines are rampant. To a certain degree you can train their direction, however, and keep them sort of manageable.

If you're going to use them for cooking be sure and plant culinary varieties. Carving types tend to be stringy and coarse, with less natural sugar.

[OregonYeti]

I've got other plants in the same patch producing great--green beans, cucumbers, tomatoes . . . so I'm thinking it's the male/female thing. I'll have to look up info on that so I can tell the difference between the two.

[MaryB]

My patch only has a few pumpkins while the squash 10 feet away in the same row are loaded no clue but this spring was really cool and dry.

[KYHeirloomer]

OY, there's no missing the difference between male and female blossoms. Whether pumpkins or cucumbers, melons or summer squash, they're all the same.

The male flowers grow off of longish stems that spring directly from the main plant stem. Just imagine a thin, light-green stick extending from the stem to the blossom.

Females have a bulbous mass at the base of the "stick;" which is also relatively shorter. That bulb is actually the ovary, and if the flower gets pollinated will grow into the fruit.

While the differences between males and females are most apparent on big-flowered types like squash, they're very obvious, even on small-flowered types like cucumbers.

[KYHeirloomer]

Mary, sometimes it has to do with specific varieties. Sometimes the weather and insect activity. And sometimes there just doesn't seem to be any explanation.

One year, for instance, I grew butternut squash, pumpkins, and acorn squash in the same area. Got a fairly steady supply of the acorns, was driven out by the butternuts, and wound up with four pumpkins from a dozen plants.

Now pumpkins tend to be less productive than other squashes. But even so, I'd have expected three or four from each plant.

You can avoid some of this problem, if you care to, by learning hand-pollination techniques. You'll increase productivity that way, and, if it's important to you, assure seed purity.

[allie]

Thanks for the planting advice! I have roasted carving pumpkins and then run through the food processor. I used it in breads and it was ok but not nearly as good as the smaller cooking varieties I have bought in the past.

Last year, the volunteer pumpkins were more of a bush than a vine. In fact, at first we thought it was zucchini or squash until the fruit started growing. This year, it was a large vine. My biggest issue in trying to grow them myself is going to be space. I just don't have a lot of space in sunlight. My front yard is huge with lots of shade (9 large shade trees of various types) while my back yard is small and only has full sun on one side.

Pollination shouldn't be a problem here. We have to get someone out to remove a hive of honey bees from behind the siding on our house!

[Hotchpotch]

>>>That, sadly, is a common problem Allie. If fruits and vegetables are visible, and accessible, they disappear. Every passerby seems to think they are free for the taking.<<<

Tis true, but my neighbor’s wife has a brilliant way of virtually eliminating this. Every year their sugar plums were taken off of their trees that boarded a busy intersection and it infuriated he husband. Being the psychologist that she is, she put up a sign one year as an experiment. It said:

“Free fruit"

That year hardly any disappeared.

Human nature – gotta love it.

[DC Sunshine]

Yeti....I reckon it was a Triffid

[MaryB]

Out of 5 pumpkin plants I ended up with 2 small pie pumpkins. I had over 40 squash from the plants in the same row(10 feet away). My cucumbers didn't do much either this year.

[KYHeirloomer]

Just out of curiosity, Mary, how did the pumpkins do on flowering? Did they put out a lot of blossoms that just didn't develop. Or was flowering also on the short side?

My cukes did surprisingly well, consider the cold, wet summer we had. But they didn't start producing until late July, and drove us out in August---which is very unusual. Down here cukes usually are finished by late June/early July.

My summer squash kept putting out blooms. But they were all males, right up until mid-August when a female finally appeared. It didn't get fertilized, however, and aborted. That was the only female from three plants. Go figure.

On the other hand, we had an incredible English pea crop. English peas are always problematical, here, because typically we have about 36 hours of spring and then are into high summer. But the years the weather cooperates (I'd say, on average, one out of three or four) the peas do fantastic.

First frost was this morning. So we'll spend the next few days cleaning up the mess.