You planted your pumpkin seeds and felt this buzz of excitement as they germinated and stung through the earth. They grew into sturdy vines with huge leaves, but none came at the exact time you were expecting flowers.
What in the world?
If you are wondering why your pumpkin (Cucurbita pepo) does not produce flowers, you have come to the right place. I've found the 5 main reasons why flowers may not appear when you expect them to.
Let's start with problem solving!
From the time you planted seeds in the soil, you should expect them to germinate within seven to 10 days. You should start seeing flowers about eight weeks (or 50-55 days) later.
This is approximately half the pumpkin growing time from 100 to 120 days, depending on the variety.
Male pumpkin flower.
Here's a tip: The first flowers you see are male. The biggest visible difference between male and female flowers is that men don't have an ovary like women. The ovary looks like a small lump right behind the flower.
Male flowers, also called staminated flowers, contain pollen on the stamen. They appear about a week or two before the sight of female or pestle-shaped flowers on the plant.
The pollen aroma in your garden attracts bees from the start and ensures that pollinators are available as soon as the female flowers bloom.
Here is another secret of the pumpkin flower that I only knew when I started growing my own pumpkins: they only last a day.
The flowers unfold at dawn. Over the next few hours they open up more and more until they are graceful golden pools at their peak of beauty.
These hours are critical to pollination regardless of whether you depend on bees or pollinate the plant itself.
The pollen on the stamen of the male flower must be transferred to the stigma of the female flower and cover the entire segmented head.
But these are birds and bees that speak for another article about pollinating pumpkins coming soon!
At the moment you only know that pumpkin flowers live a short but significant life. At the end of their first day of life, they shrink.
The second thing to keep in mind is that they only appear in the middle of the plant's entire life cycle.
So if you see vines and leaves but no flowers, there are two things to consider:
- The plant can be developed almost to the extent that flowers can form, but not entirely. Check the germination date when you have written it in your garden journal or a photo with a date stamp taken on your phone. (I often rely on the latter method!) If it is only 30-50 days, the flowers are not yet ready to bloom.
- You may miss the flowering period. Perhaps you haven't had a chance to step into your garden in the morning or all day, and in the evening you only see shrunken stumps on the vine. You are not sure if it was ever a flower or if it is a strange mutation. It is likely that it was flowers. And if female flowers were pollinated, you would soon see that this rounded ovary turns into a beautiful pumpkin!
2. The floor
If you stop seeing flowers after more than 55 days, the soil on which your pumpkins grow may contain too much nitrogen, which contributes to beautiful leaves but not to flower production.
Or maybe it has a processable amount of nitrogen, but not enough phosphorus.
Phosphorus is responsible for planting fruit and is an integral part of the flowering process.
So if you planted your pumpkins in fertile soil a few months ago, but haven't fed them since then, it's time to feed those hungry pumpkins!
Choose a to promote flowering while supporting leaf growth 5-10-10 NPK Fertilizer so your plants get more phosphorus and potassium than nitrogen.
What to do if you suspect too much nitrogen is the problem? How do you reduce the amount of a chemical element in the soil?
Next year, try planting corn that is high in nitrogen next to your pumpkins.
Keep in mind that pumpkins also need nitrogen so you don't try to eradicate or even greatly reduce the content.
The main thing is that some other plants will benefit from it while adding phosphorus to make these plants bloom.
You can learn more about them The best companion plants for pumpkins in this guide.
3. The sun
Another reason why you may not see flowers is the lack of sunshine.
Like many plants, pumpkin vines grow weakly and long-legged, without light. And these plants love the sun – they need at least six to eight hours a day, preferably more.
If they only have four or five hours of sun and spend the rest of the day in the shade, they may not produce flowers when they are supposed to.
So keep an eye on how much sun your plant gets for a whole day. Don't be afraid to carefully transplant it to a new, sunnier place if necessary.
4. Too much heat
It is possible that your plant will be stressed under a large heat wave and drop immature buds before they can open.
While pumpkins love sunshine, they don't like to get too hot.
If daytime temperatures permanently rise above 90 ° F at night and there is little to no break, your plant may be too stressed to produce flowers that consume a lot of energy and nutrients. Instead, it switches to a kind of survival mode.
You might be skeptical that the sun could do such damage to a sun-loving plant.
But take this example that happened to me recently: I sowed several Rhubarb plants from seeds in containers this winter.
As soon as our extra long summer days in Alaska came, they bloomed on their warm windowsill and grew thicker stems and huge (for their age) leaves.
So I decided to put one outside to harden myself. Since rhubarb loves sunshine, I thought spending a few hours in fresh, relatively cool 60-degree sunlight would do the plant good.
I was wrong. It withered.
Photo by Laura Melchor
It got too much sun and the black container didn't help.
Now I give my remaining rhubarb plants fresh, shady and partly sunny air every day and they have stayed happy.
The healthy rhubarb is to the left of his poor dead sibling. Photo by Laura Melchor.
So if pumpkin blossoms fall and you suspect overheating is the culprit, do the following:
- Make sure to give the plant plenty of water on the hottest days and cover the entire drip line with a to use the tree language light mulch like strawto divert heat.
- Try shading your plants with a shady towel and hoop during the hottest part of the day.
Just like us I need help to stay cool in the middle of a hot summer dayOur plants too.
5. There is a mushroom among us
I'm sorry, I couldn't help pulling this beautiful rhyme into it. But I really think there might be mushrooms under your pumpkins, and that could be the reason why the vines don't produce flowers.
Powdery mildew is an extremely common disease caused by fungi, and pumpkins are particularly susceptible.
If you see powdery white stuff on your pumpkin vines or leaves, take quick action. Remove the affected leaves and reach for one organic fungicide used to treat the plant.
Some fungicides are preventive, others are designed to treat an existing infestation, and some do both. So pay attention to what you spray your plants with.
Spraying an existing fungal outbreak with preventive fungicide doesn't do much, while adding a curative fungicide to uninfected plants can be a waste of time and money.
And if you live in a particularly humid, rainy area, it is worth spraying your plants early with preventive fungicide.
When removing leaves, also wash your hands between plants and even between infected and uninfected leaves of the same plant.
The last thing you want to do is pluck a moldy leaf from a vine just to touch a healthy plant or leaf nearby with the same hand and spread the spores.
Any fungal infection can affect flowering if the disease affects the general health of the vines and leaves, delays flowering, or even kills the plant.
But with quick and early treatment you should be able to avoid this.
The best way to prevent fungal infections is, of course, to avoid overhead watering and to ensure that there is sufficient airflow around your plant.
Combined with the habit of checking your pumpkin leaves and grapevines for signs of disease daily, you can make sure your plants are healthy enough to bloom and fruit.
May they bloom and grow forever
Well, maybe not forever. But now that you know the five main causes that can cause a lack of flowers, you are ready to make these plants healthy and blooming.
And you know what that means – baby gourds will soon come to a plant near you. Oh, the excitement!
In the meantime, keep an eye on these pumpkins, as my three-year-old does. He loves to look after them. He even uses binoculars to get a particularly close look.
Photo by Laura Melchor.
Have you ever looked at pumpkins that didn't want to bloom? Let us know in the comments!
And remember to read our other articles growing pumpkins in your garden:
About Laura Melchor
Laura Melchor grew up and helped her mother in the garden in Montana. As an adult, she brought her gardening skills home in Alaska in cold weather. She is particularly proud of the flower beds that she and her three-year-old son built with stones that were dug up from their small homestead in Alaska. As a freelance writer, she contributes to several websites and blogs on the Internet. Laura also writes novels and has an MFA from the Vermont College of Fine Arts.