Pumpkins can reach impressive sizes, but so can their vines.
Pumpkin vines are the stiff, trailing stems that spread across the ground from the rooted growing point. There are three parts to a pumpkin vine:
- The main vine: Where the fruits form
- Secondary vines: Produce leaves for photosynthesis
- Tertiary vines: Produce small leaves
Depending on the variety, the main stem can reach up to 30 feet long during the growing season. Pumpkin vines can be left to spread on the ground, trained to grow vertically on a trellis or pruned to control growth.
In this article, you’ll learn more about the amazing pumpkin vine- how it’s both tough and delicate. We’ll cover three ways to get the healthiest, strongest pumpkin vine you can- because that gives you the best for healthy, strong pumpkin fruits!
Ready to learn more? Let’s jump in!
What Does a Pumpkin Vine Look Like?
The typical pumpkin vine is a stiff green stem that lies along the ground, with its leaves held above it on secondary upright stems. The diameter of a pumpkin stem is anywhere from the size of a quarter to a silver dollar.
The sides of a pumpkin vine aren’t smooth and round. Instead, each vine is ridged along its length, from tip to growing point, and it’s covered in stiff, scratchy “hairs” that will irritate your skin if it gets scratched– so long sleeves only at harvest time!
How a Pumpkin Vine Grows
A pumpkin vine first appears soon after the first true leaves, but at that point, it’s very small. As the vine grows, it develops into a main vine that branches into secondary and tertiary vines.
The main vine is the one that emerges from the growing point and lays along the ground. Some pumpkin plants may produce two or three of these per plant. These will grow the most in the early part of the season, as it produces leaves as well as secondary and tertiary vines.
Pumpkin flowers and fruits grow mostly on the main vines.
Secondary vines, also known as runners, split off from the main vine. Their job is mainly to produce extra leaves to power photosynthesis and feed the main vine and its fruit.
The large leaves also provide shade that prevents the fruits from sunburn, keeps the soil cooler in hot weather and slows moisture loss to evaporation.
These vines grow mostly in the early to middle part of the season but may continue to add inches throughout the year. This isn’t always a good thing, as we’ll talk about in the “How to Prune Pumpkin Vines” section below.
Tertiary vines grow right off the secondary vines. Even though they also put out leaves and add to photosynthesis, they aren’t really necessary. Plus, pruning them off usually redirects the plant’s energy into its fruit instead.
3 Ways to Keep Pumpkin Vines Healthy and Strong
Now that you have a basic understanding of how a pumpkin plant produces its vine, let’s look at how you can keep this literal lifeline for your plant healthy.
1. Prune Pumpkin Vines for Optimal Production
Pruning is the process of cutting away certain plant leaves or stems to promote growth and strength in the remaining areas. While it may seem strange at first to cut off healthy growth, there’s a method to the madness.
Why Should You Prune Pumpkin Vines?
Pruning pumpkin vines isn’t totally necessary- your plant will still survive and produce a harvest even if you don’t do any pruning at all.
But strategically trimming pumpkin vines can serve more than one purpose:
- Controls size
- Redirects energy into flower/fruit growth
- Allow more light and airflow to reach fruit in the interior
- Makes it easier to harvest pumpkins in fall
Pumpkins can take up a lot of space, and not all that foliage is necessary for a bumper crop. Melody Estes, Landscape Design Gardening Supervisor and consultant at The Project Girl, agrees. “Pruning pumpkin vines is a useful way to manage the growth of your pumpkin plants, and it can help you produce bigger and juicier pumpkins.”
But Melody cautions, “It’s important to make sure that you don’t prune off too much, or else you might end up with stunted growth.”
When to Prune Pumpkin Vines
If you’re working with mini or small pumpkin plants, you probably won’t need to prune the main stem at all. But if you’re growing a larger pumpkin variety, trimming the end off the main stem can help control the overall plant size. If you do choose to trim the main stem, wait until it’s in the 10-15 foot length range.
Hold off on doing any trimming or pruning until you can clearly identify several fruits forming. If you prune too early, you might accidentally rob yourself of pumpkins.
How to Prune Pumpkin Vines
Clean cuts prevent ragged edges and damage to the vine that may draw pests, so use a pair of strong pruning shears with sharp blades to do your pruning.
Always sanitize your cutting tools before you make any cuts to any plant. Clean the blades off with alcohol and allow to fully air dry, or soak your pruners in a 1:10 bleach/water solution for a few hours and allow to air dry.
The actual process of trimming pumpkin vines is pretty straightforward. Start by pruning off any tertiary vines– they’re the smallest vines with the smallest leaves. Simply cut them back to where they join the secondary vines.
Secondary vines are useful because they add photosynthetic power to the plant, but it’s easy for them to outgrow a trellis or a garden bed. For these, just shorten them by cutting them back to a spot where a leaf joins the stem.
As mentioned earlier, the main stem is one you should generally leave alone unless it too begins to outgrow its space or you’re trying to grow just a few extra-large fruits. In that case, you can cut off the growing tip about 5-8 feet beyond a fruit you want to keep. This stops the plant’s forward growth and focuses the energy on any developing fruit.
This video from Gardener Scott does a great job of outlining the pumpkin pruning process:
2. Train Pumpkin Vines on a Trellis or Tower
Either in person or in photos, you’ve probably seen a field of pumpkins with vines growing in every direction. But there is another way to successfully grow many types of pumpkins- vertically.
Let’s take a look at the why and how:
Why Should You Trellis Pumpkins?
Pumpkin plants can take up a lot of room in the garden, and trellising is a great way to grow pumpkins in a small garden or maximize space in a medium-to-large garden.
It has the added benefit of lifting pumpkin fruits away from the soggy ground where they may rot and keeping the developing fruit from the reach of slugs and other ground pests.
Growing your pumpkins vertically also allows for better airflow, helping to lower the risk for certain fungal diseases. And finally, trellising lets you keep an eye on your pumpkin’s development and makes it easy to harvest at just the right time.
The Best Pumpkins for Trellising
You’re better off keeping large and giant pumpkins on the ground rather than a trellis. Instead, look for types that produce fruit weighing less than 10 pounds apiece so both the trellis and the vine can hold up under the weight.
Here are a few varieties that we recommend as the best pumpkins for trellising:
- Baby Bear
- White Queen
- Sugar Pie
- Jack Be Little
How to Trellis Pumpkins
First, choose a trellis. An A-frame support or garden arch work well, but you can also use a chain-link fence, lattice or wooden trellis if you already have one. Set it up where you intend to grow your pumpkins.
Sow your seeds or plant your transplants within a few inches of the trellis’s base.
Once the vines on the new plants are long enough to reach the trellis, you can start attaching them. Use loops of a soft garden tie material or an old t-shirt cut into strips to loosely hold the vines onto the structure.
Be gentle as you manipulate the vines, and don’t tie the material too tight, or it may chafe the skin of the vine and/or eventually snap right through it as it grows wider. As natural climbers, pumpkin vines wind around anything they come into contact with, so you don’t need to be overly aggressive when attaching the plant to a trellis.
3. Handle Your Pumpkin Vine With Care
Even though it’s large and appears imposing, a pumpkin vine is actually quite delicate and requires a gentle touch. I found this out the hard way when I waited just a bit too long to re-direct the main vine towards the front of its container instead of creeping over the edge of its neighboring container.
Where the vine had to shift, it caused a split in the side of the vine itself:
Obviously, this was worrying when it happened, but the plant continued to grow fine afterward. However, there’s an increased risk for pests and or disease formation at the damaged area, so I’ll have to keep a close eye on it.
So it’s a lesson I’ll take to heart and advise you to do the same: Don’t wait to move the vine if it’s growing in a different direction than you want it to take long-term.
In my case, I should have guided the vine in the proper direction as soon as it started growing. Or if you want to trellis your pumpkins, place the trellis immediately after planting your seeds or seedlings. Then train the plant to grow on the trellis as soon as the first vine tips appear.
Another way to keep your pumpkin vine intact and safe is to be aware of its location. Pumpkin vines grow fast and can sprawl all over the garden, and they often make their way surprisingly far outside the pumpkin patch before you ever know it.
If you accidentally step on a vine and severely break it below where a pumpkin is forming, you may lose that fruit. Also, a damaged vine is much more susceptible to disease or pest infestation.
So it’s worth it to watch your step when you’re working in the garden!
Care Tips for Pumpkin Vines
Pumpkins aren’t hard to grow, but you’ll get the best harvest by following a few guidelines:
- Plant in full sun. Pumpkins don’t grow very well in shade.
- Have good watering practices. Water pumpkins consistently, but avoid watering every day since this blocks oxygen from reaching the roots. Instead, water deeply every second or third day, watering directly at the roots and not the foliage.
- Fertilize regularly! Pumpkins are heavy feeders, and they need fertilizer with extra potassium and phosphorus to grow the biggest and best pumpkins possible. For more on this, check out our post on how to fertilize pumpkins.
- Keep an eye out for pests. It’s much easier to control pests early before the infestation has set in. Pumpkins aren’t huge pest targets, but they can experience attacks from aphids, squash bugs, and slugs, especially when they are younger and tender.
- Don’t overcrowd the pumpkin patch. Pumpkins are vulnerable to fungal diseases, like powdery mildew, that often spring up in low-airflow conditions. Leave plenty of space between plants to keep the air pure and moving freely.
What to Do With Pumpkin Vines After Harvest
Pumpkin vines create a lot of green material, so don’t let it go to waste! Here’s what you can do with pumpkin vines after a harvest:
- Add them to your home compost.
- Chop them up and turn them under to decompose over the winter.
- Allow them to remain on the soil surface through the winter to provide shelter to beneficial insects.
- After they’ve died and dried out, use the leftover vines as fuel for your fall bonfire.
Frequently Asked Questions about Pumpkin Vines
We hope this helped answer your questions about pumpkin vines, from pruning to trellising to general care. If you have any more questions about this garden favorite, check out our other pumpkin articles or drop us a line in the comments below!