When to prune pumpkin vines

When you first start gardening, it’s usual to think of pruning as a fall or winter job. However, with pumpkins, it’s far better to get started now, and knowing when to plant pumpkins and when to pick pumpkins off the vine will ensure your harvest is at its best.  While major work (removing big vines and so on) is still best left until winter, you’ll find that late summer pruning is a clever way of getting more crop the following year without encouraging too much regrowth. The idea is to mildly shock the plants by removing many of their small, young shoots while in leaf, thus making the plants change their manner of growth. Obviously, if you’re trying to grow up and train a young tree, pruning is best left until winter, but for established trees and bushes, summer snipping is better.

How to prune pumpkin vines

Before you start to prune pumpkin vines, you need to understand their growth cycle. Once the main pumpkin vines of the plant have established, you’ll start to notice secondary and tertiary vines also starting to appear. All of these vines will need to be pruned to promote proper pumpkin growth – and also covered in soil to prevent disease.  We’ve had a nice warm summer, which is important in the setting and initial stages of fruit development. But in the few weeks prior to harvesting, there are certain things to do:  As well as pruning pumpkin vines. It is also important to control weeds at all stages – even in the last few weeks. Don’t hoe near to the plants as their very shallow roots may be damaged. You should have pinched off the fuzzy ends of each vine after a couple of pumpkins were formed to focus the plant’s energies on the fruit. If you didn’t, do it now.  If you are trying to grow a show prize-winner, select just two or three prime candidates and remove all other fruits and side shoots. As the fruits develop, they should be turned (with great care not to hurt the vine or stem) to encourage an even shape. Pumpkin vines are actually very delicate; try not to cause damage to the stems and leaves when pruning as this reduces the quality of fruit.

1. Understand how pumpkin vines grow

You might be surprised to know that all pumpkin vines grow in the same manner, regardless of the species of pumpkin. They start spreading rapidly once growth appears, therefore, it is necessary to keep them maintained and in proper health.

2. Take precautions 

3. Cut the tertiary vines

Use pruning shears to trim the tertiary vines. These are the vines that are growing out of the secondary vines and they need to be pruned as soon as they start to develop. Cut them from where they meet the secondary vines. 

4. Cut the secondary vines 

Measure around 10-12 feet along the joint where the secondary vine meets the main vine. After measuring, cut with hand pruning shears. 

5. Cover the vines with soil 

It is vital to cover the vines with soil to prevent disease after the initial pruning stage as once cut, the plant will be more prone to disease and infection.  To minimize and prevent fungus from entering your pumpkin plant, cover the cut ends of the secondary vines with soil. ‘Make sure to use rich soils; you can add mulch for natural enrichment,’ says Chris Rusch, member of the Douglas County Master Gardeners program (opens in new tab) at Oregon State University.

6. Cut the main vines 

It is important to let the main vine fully develop. You will know it has when fruit starts to emerge. Trim these vines with your pruning shears to around 10-15 feet beyond the last pumpkin fruit on the vine. A single pumpkin may have between 2-3 main vines.  As this main vine continues to develop, continue to prune them as and when is required to ensure that all the nutrients concentrate on the actual pumpkin fruit instead of the main vine.  Once again, cover the cut ends with enriched soil to prevent disease and fungus from entering the plant. This will also help to preserve moisture.