When I first started gardening, I thought the only way to keep a pumpkin vine alive and well was to let it grow in all directions.
It turns out that this isn’t always the case.
Even though you don’t have to trim the vines, doing so can help you get a bigger harvest and more pumpkins.
Gardeners trim pumpkin plants for three main reasons: to keep them from choking out other plants in the garden, to make them easier to take care of, and to let more airflow between the leaves, which can help keep diseases at bay.
Also, by giving up some of the younger fruit, the plant can put all of its energy into growing the pumpkins that are still there.
You’ll need to know how to take care of your pumpkins, which you can learn more about in our growing guide.
You’ll find out the following:
Anatomy of a Vine
Before we get into when and how to trim your pumpkin plant, it’s important to know a few things about how they grow.
First, there’s the main vine, which is the one directly connected to the roots that grow out of the ground. When you look at your plant, it’s the thickest one you’ll see.
From the main vine grow smaller vines called “runners,” which, if left to grow on their own, will make more roots.
As you’ll see below, you can also bury the stem to make the plant grow more roots. These runners can then make more runners, which are called tertiaries.
Any of these vines can produce leaves, flowers, and, as a result, fruits. But tertiary runners should be cut off as soon as you see them so they don’t steal nutrients from the main and secondary vines.
It can be hard to tell which is which, but it’s worth taking the time to get to know your plant so you’ll know what you’re looking at when it’s time to trim.
When to Prune
Wait until they are at least 10–15 feet long before you trim them. In an ideal situation, you should wait until you have two to five mature fruits on larger varieties or 10 to 12 small gourds on smaller ones.
When I was growing tomatoes earlier this year, I saw that the lower leaves were starting to get a spot on them.
I started to worry, so I looked up what I should do to keep the plant alive. It turned out to be a fungal infection, and the solution was simple: cut off the affected leaves and prune the lower part of the plant to get rid of the leaves.
So, if water splashes up from fungus-infected soil, it won’t spread the fungus to new leaves at the bottom.
It worked, and now my tomatoes are doing very well. But the edges of my young pumpkin leaves soon got a few small white spots, which made me worry again.
This time, I didn’t do any more research before cutting back a few leaves when the stem was only about a foot long.
I don’t know what the spots were, but the plants now look fine.
But they are growing slower than they probably would have if I hadn’t carelessly taken off the leaves and messed up their early development.
Here are a few more tips for knowing when to trim:
- When the main vine is 10 to 15 feet long, measured from the plant’s center, cut it.
- When the secondary runners are about 8 to 10 feet long, cut off their tips.
- As soon as you see tertiary vines, which grow from the runners, you should cut them back.
- It really is that simple.
Now, let’s talk about how to cut back your pumpkin plants.
How to Trim
You only need a pair of gardening gloves, a pair of pruning shears, and a tape measure to prune.
To cut the main vine, stand 10 to 15 feet away from where the plant grows out of the ground in the middle. Don’t cut yet if there’s a fruit that’s already grown and you want to keep it.
Instead, measure about five feet past the last healthy fruit and make your cut there.
But if the fruit is soft or if it is the sixth or seventh gourd on the plant, including those growing on the secondary runners, cutting it off can help your plant put its energy into the other five squashes.
This means bigger, tastier, prettier pumpkins for you.
To cut back secondary runners, measure about 10 feet from where the runner shoots off the main stem and cut there.
It’s best to cut back tertiaries as soon as you see them because they take food and energy away from the main and secondary vines.
After you make a cut, bury the cut end an inch or two deep in the soil and cover it with mulch.
This will help keep the plant from drying out and make it harder for pests and diseases to take hold.
Also, if you keep the soil damp, it should grow a new root system where it was cut, which will give your growing gourds more food.
If you keep the plant neat and trimmed, it will be more likely to grow strong, healthy squash. And isn’t that what every pumpkin farmer wants?
No Rat’s Nest Here
You don’t have to prune your pumpkin plants. Even if you let them grow wild, you’ll still get some fruits.
But that would be like letting a toddler’s curly mop of hair grow and grow without brushing or trimming it to keep it healthy.
Don’t be afraid to get out those pruning shears and get to work on your pumpkin patch.