The arrival of winter squash is one of the first signs of fall. These classic and delicious squash are a great addition to any garden but require a little bit of tender love and care in the form of pruning to help them meet their full potential.
You should prune your winter squash as a way to promote fruiting in your plants, improve accessibility to the squash, and prevent the spread of diseases. Use garden clippers to trim back the unruly vines and make sure to prune no more than 20% of the foliage.
Although it can seem like winter squash has a mind of its own, don’t let that intimidate you. I’ll share my tips on how and when to prune winter squash and what you need to look for to keep your squash in check.
Advantages to pruning winter squash
The benefits of pruning winter squash are well worth the time and effort. While it’s not a necessity, you’ll notice a difference in the quality of your squash and your squash beds will feel much more manageable.
For those of us gardeners working with smaller spaces, pruning back out-of-control squash can greatly improve accessibility.
Because squash vines tend to spread out, it’s easy for them to start invading other parts of your garden where you don’t want them. You can trim squash vines that have spread into your walkways or that have started to smother the other veggies that you’re growing.
Pruning back the squash leaves also makes for an easier time harvesting. Fewer leaves make the fruit easier to spot and the prickly leaves don’t get in the way and scratch and irritate your skin.
Pruning the vines can also help you distinguish which plants are which when you’re growing more than one variety. If you’re working with limited space, consider growing a compact winter squash variety.
Later in the season, when the squash have set their fruit, you can trim back the vines to encourage ripening. By doing this, the plant is putting its energy towards developing the fruit instead of spreading its vines and leaves.
It also helps to pick varieties that have higher yields so that you can get the most fruit possible from your winter squash.
Don’t worry if the vines you’re cutting have flowers on them. You’ll be doing this pruning later in the season so these flowers will not have the time to develop into edible squash before the frost kills them.
Just remember to pay attention to what you’re trimming. You don’t want to accidentally cut off a squash before it’s had the chance to ripen.
Prevents disease spreading
Pruning winter squash leaves can help prevent the spread of common diseases like powdery mildew or anthracnose. You can remove any diseased leaves to keep them from spreading to the rest of the plant.
Keep in mind that if most of the leaves on your plant are showing signs of the disease then removing all of them won’t save the plant. This method only works if the disease is caught early enough and is only on a couple of the leaves.
Pruning the leaves also increases airflow around the plant making it much more difficult for mold or mildew to travel.
How to prune winter squash
How you prune your winter squash depends on what part of the plant you’re looking to prune. You have the option between the vines, the leaves, and the flowers. I’ll walk you through how to do all three.
With all three of these options, you just want to make sure that you don’t prune too heavily, especially if your winter squash hasn’t set fruit yet. If you’re ever unsure, it’s better to err on the side of caution and prune only a small amount.
As a rule of thumb, I don’t prune any more than 20% of the foliage.
To prune the vines, you’ll want to use a pair of garden clippers to do the cutting. Cut the vine about a few inches from where it’s developing a fruit, taking extra care not to prune too close to the fruit.
When I cut back winter squash vines, I look for the vines that are either significantly longer than the other ones or vines that have started to wander into walkways or other beds. These vines are sometimes called runners and can take energy away from the fruit.
Pruning the leaves is really only necessary when trying to prevent the spread of disease as I mentioned earlier. When you prune back the vines you end up taking a lot of leaves with you anyway so it’s like a two-for-one deal.
You can either clip back leaves at their base with garden clippers or you can pinch them off with your fingers.
Again, if your winter squash hasn’t set fruit yet, prune sparingly. If you prune the leaves too heavily, your plant may not be able to photosynthesize as it needs to and can have stunted growth or low squash yields.
Pruning winter squash flowers is a great way to get more fruit from your plants. Squash have both male and female flowers with the female flowers being the ones that form the squash.
The male flowers can be pruned back to promote fruit development from the female flowers. Just make sure not to harvest all of the male flowers or there won’t be anything left to pollinate the female flowers, leaving you with no fruits.
Pruning the flowers is as easy as carefully picking the flowers off with your fingers.
Something else that’s so great about squash flowers is that they’re completely edible! So make sure to save the flowers you prune to fry up or add to your salads.
When to prune winter squash
In most cases, you won’t want to prune your winter squash until it has set and developed all the fruit you want it to. Your squash should be ready for pruning around late summer or early fall.
This will speed up the ripening process and your winter squash will be ready for harvest by the time September and October roll around.
You may notice that vines you’ve already pruned end up growing back. This is normal and they can simply be pruned again.
Make sure not to do any pruning after heavy rains or while the leaves are wet as you run the risk of spreading disease among your squash.
When I notice vines that have started to creep out of their beds but I’m not quite ready to prune, I train them to get them to go where I want them to.
To train your squash, carefully lift the vine and move it in the direction you want it to go. For me, that usually means pointing the vine to the left or the right or tucking it back into the bed where it belongs. Your squash will continue to grow in the direction that you point the vines.
If you’re growing squash on a trellis, the process is very similar. As your vines grow, help them continue to grow upwards by wrapping the vines around the trellis. This helps the tendrils find something to attach to which will strengthen the plant so it can support the weight of heavy squash.
I like to check on my winter squash for training about once a week but depending on how much you’re growing, you can train your squash as needed.
Pruning your winter squash is a quick and easy way to improve the quality of your fruit. You have less disease pressure, your fruit will ripen quicker, and it saves you space in your garden. All these are a win in my book!
As long as you prune after the fruit has set and take care not to prune too heavily, you’re sure to have a fantastic squash harvest this fall.