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Should Potato Plants Be Pruned

If you are new to potato gardening, you may be experiencing unexpected challenges. Although potato gardening is relatively easy, there are still some things you may not have realized about caring for them. You did your research and noticed some people say you should prune your potato plants, while others say you should not. This depends on the variant of potato you are growing and the size of the potato you want to harvest. So, the question is, should I prune my potatoes, and if so, how much should I take?

In some cases, potato plants need to be pruned to prevent them from falling over and growing along the ground. However, it depends on the size of potato you are trying to grow and how quickly you need your potatoes to mature.

Now that you know you can prune your potatoes, let us talk about how to prune them, the benefits of pruning potato plants, and the drawbacks, or cautions, to pruning potato plants.

When should I prune my potato plants?

Just before harvest is the time to prune, between 10 and 20 weeks after planting, your potato plants will begin to bloom flowers, signaling they are close to reaching full maturity and will be ready to harvest soon.

How do I prune potato plants?

Pruning your potato plants is not difficult since you are simply cutting back the green. However, there are a few factors that go into pruning potato plants. Knowing when to prune them and how much to prune them are important notes to consider before attempting to cut your potato plants back.

  1. Prune the potato blooms – Potato plant blossoms signify your plant is near full maturity, and the small tubers are formed. There are a few ways to prune your potato blossoms. You can either cut the flowers off with a trimming tool (a pair of shears) or carefully pluck them off with your fingers.
  2. Prune the potato vine – Wait until the vines and leaves have wilted. Then cut the plant evenly down to an inch above the soil. 
  3. Wait for about two weeks – once your potato plants are pruned and cut down, there is a two-week period where your potato skins will thicken, allowing them to store longer once they are harvested. It is recommended not to water your potatoes during this time.

Pruning Ornamental Potatoes

Ornamental potatoes can be pruned differently than edible potatoes. Potatoes, such as Ipomoea, can be pruned anytime the plant has bushed out and outgrown its surroundings. These fast maturing potato vines will continue to grow and branch out, taking up any available space. 

Ornamental potatoes can be pruned to the ground, unlike edible potatoes. You can prune these plants as needed throughout the spring through fall months to contain them in their own growing space or wait until the vines begin to wilt and then prune them.

Benefits to pruning potato vines

There are several benefits to pruning potato vines if it is done correctly:

Pest infestations and Disease

If you notice your potato plant has been infected with disease or is being attacked by pests, you can carefully prune the infected pieces of the plant to try and save it or the other potato plants around it. Pruning the infected leaves or vines allows the plant to focus on growing rather than trying to fight the infection or infestation.

Plants that have grown too big or tall

Potato plants that have been over-fertilized, or have received too much nitrogen, often grow too big to maintain themselves. In this case, you can prune them down to help keep them from toppling over.

A potato stalk that has grown too tall can become too heavy to hold its own weight and may fall over. This puts it at risk of disease or pest infestations if it is allowed to continue to grow on the ground. Tall, lanky potato vines that grow too big will spend too much energy growing foliage, not leaving enough energy to grow potatoes.

Sunlight and pruning

When certain potato plant species are allowed to grow a lot of foliage, they will continue to grow if not properly maintained and pruned. This can cause them to grow leggy and weak because their stocks will not get enough sun. When they become leggy and begin reaching for the sunlight, they are more likely to fall over or be blown down by high winds or rain.

By pruning your potato’s leaves and vines, you open your potato plants to the sun, allowing them to grow strong thick stocks.

Cautions for pruning potato vines

There are a few tips to keep in mind before pruning your potato vines:

  • Maturity – Make sure your potatoes tubers are ready for harvest. The potato stalks will begin blossoming flowers, and the vines will begin to wilt and turn yellowish-green. This is a sign they are ready. If you trim your potato vines before the tubers are ready, the potato plant will not get the proper nutrients to make food fully mature.
  • Leave an inch – Do not cut the plant any lower than an inch above the soil surface because you could accidentally expose the tips of your shallower potatoes. This could cause them to turn green from the sun and become inedible and hard.
  • Harvesting after pruning – Leave your potatoes in the ground at least two weeks after pruning them before you harvest them. Their skin is still soft and needs about two weeks to harden and prepare for storage.
  • Pruning stunts potato growth – Keep in mind that pruning a potato’s vine and foliage can stunt your potato’s growth if they are not yet fully matured. If you prefer smaller potatoes, then this should not be a problem. Otherwise, be sure your potatoes are fully grown before pruning them by checking if they are blossoming or if their vines are turning yellow and beginning to wilt.

Conclusion

Any plant can be pruned. However, timing is everything when it comes to pruning potatoes. Before pruning your potatoes, make sure they are fully matured if you want to harvest full-size potatoes. Keep in mind the variety of potatoes you are growing and how much water, sunlight, and pruning they require to ensure the best yield.