6 Reasons Why Pumpkins Split on the Vine

When making a vegetable garden, pumpkins are always on top of every home gardener’s list. Pumpkins ripen in the autumn, and it is enjoyable to watch them grow larger by day. But what if you check your pumpkin only to see it has split open on the vine? 

Here are 6 reasons why your pumpkins may split on the vine:

  1. You’re giving it too much water.
  2. You’re experiencing a late autumn.
  3. You’ve planted the pumpkins too early.
  4. It’s in the pumpkin’s genetics.
  5. The weather is inconsistent.
  6. You’re applying fertilizer at the wrong time.

Let’s take a more detailed look at what causes pumpkins to split on the vine. We’ll also discuss valuable tips on how to avoid this problem and get a perfect crop every year.

1. You’re Giving It Too Much Water

One of the main causes of pumpkins splitting on the vine is due to excess water. The pumpkin absorbs the water faster than the skin can expand to hold it, causing the rind to split. This process typically happens over a few days if the pumpkin is over-watered regularly.

Overwatering a pumpkin is more problematic in the autumn and when the pumpkin has partially ripened. Pumpkin plants grow rapidly in the summer and may handle the extra water. However, as the pumpkins develop, the rind will start to harden, and the plant will slowly lose its leaves and die.

If you water the plant after the pumpkin has partially ripened, it may cause the rind to crack. This problem is common amongst pumpkins, butternuts, and watermelons and usually happens at the end of the growing season.

Fortunately, you can reduce the risk of your pumpkin cracking open by watering the plant moderately and reducing the amount of water you give it as the season progresses. While it may be tempting to water the plant more to get bigger pumpkins, doing so may also increase the risk of damaging them.

2. You’re Experiencing a Late Autumn

Pumpkins should ideally be harvested mid-autumn before the first frost. As the weather gets cooler, the pumpkin will gradually ripen and become orange. The cooler weather in Autumn also allows the vegetable to develop properly. Pumpkins that start ripening in early autumn can be left on the vine for longer and usually grow bigger.

However, if summer is unusually long, the pumpkin will experience a late growth spurt due to the warmer weather. This may cause it to intake more water from the soil, causing the pumpkin to crack on the vine.

Warmer weather will also cause the outer rind of the pumpkin to harden, even though the pumpkin may not be fully ripe. If you’ve harvested pumpkins that aren’t properly ripe even though the plant has died, it’s probably because of a late autumn.

While there’s not much you can do about a late autumn, you can adjust your watering quantity and time according to the weather. If the pumpkins grow faster due to hotter weather, try to cover them or place them in an area with more shade to prevent the rind from hardening too early.

3. You’ve Planted the Pumpkins Too Early

If your pumpkins are splitting on the vine, it’s usually because they are ripening too early. This is either caused by an unnatural growth spurt or because you’ve planted the pumpkins too early. Planting pumpkins too early will cause them to ripen in the summer, resulting in smaller pumpkins, split pumpkins, and other problems.

The ideal time to plant pumpkin seeds is early summer if you live in a hot area and mid-summer if you live in a cooler area. However, this depends on the humidity in your region and how soon winter arrives. If you live in an area with hardly four months of hot to moderate weather, it’s better to plant your pumpkins in early summer.

The type of pumpkin also affects when you should plant it. Some pumpkin varieties will produce mature pumpkins in around 90 days, while other varieties may take up to 4 months before you can harvest ripe pumpkins. Always plant the pumpkins so that they start to ripen in early autumn, thus you can harvest them before the first winter frost.

So, if your pumpkins are splitting on the vine in late summer, try planting the following year’s crop a few weeks later for better results.

4. It’s in the Pumpkin’s Genetics

While it may seem odd that your pumpkins are splitting on the vine, it’s not an unnatural occurrence. Did you know that splitting was originally in the genetics of pumpkin and butternut plants? This is an effective method of helping the plants propagate their seeds, especially if they’re on the ground.

While most of your pumpkins may not split on the vine, there’s no need to be worried if one or two split open. Most pumpkin seeds nowadays are from pumpkins that were bred not to split. However, if your pumpkins are always splitting on the vine, change your variety or get special seeds.

Specially developed seeds are perfect for home gardens since they give better results and are more durable than regular seeds. You’ll have fewer problems with plants grown from special seeds, and your pumpkins won’t split open as often.

5. The Weather Is Inconsistent

Sometimes, you may plant the pumpkins on time and water them properly, and still get pumpkins that split on the vine. If this is caused by inconsistent weather, there’s not much you can do about it.

The weather may become cool at the end of autumn and then suddenly turn hot. As the weather cools down, the pumpkin plant will slow down its growth, and the pumpkins will start to ripen. However, the sudden warm temperatures may cause the pumpkins to grow rapidly, causing the pumpkin to split.

The opposite can also be a problem. If the weather suddenly turns cold or winter arrives early, the pumpkins will ripen too early, increasing the risk of rotting on the vine. Unfortunately, you can’t control the weather changes, but you can adjust your care routine to reduce the risk of damaging your crop.

6. You’re Applying Fertilizer at the Wrong Time

Overwatering pumpkins isn’t the only cause of growth spurts. Applying fertilizer at the wrong time can also cause the pumpkin plants to grow too fast, leading to split pumpkins. The best time to apply fertilizer to pumpkin plants is in the early summer after germination and during the first half of the plant’s growth stage.

However, applying fertilizer in late summer or after the pumpkins have flowered may cause the plant to grow well into the autumn. This could cause problems such as premature ripening, or the pumpkins may split on the vine.

Always follow the correct guidelines on when to apply fertilizer to your pumpkin plants and choose the best type of fertilizer. Ideally, you should  rotate your pumpkins to keep the soil healthy. Since pumpkins are planted in early summer, fertilizing the soil in spring is ideal.


Here are answers to some common questions regarding growing pumpkins.

How Can You Prevent Pumpkins From Splitting on the Vine?

You can’t always prevent pumpkins from splitting on the vine. Still, you can reduce the risk of this occurring by planting the pumpkins at the right time, avoiding overwatering, and following the correct fertilization guidelines. 

Also, protect the pumpkins from sudden weather changes and harvest them earlier if you’re experiencing late autumn.

How Often Should You Water Pumpkins?

You should water your pumpkins once or twice a week for optimal growth. Watering your pumpkins every day can cause problems such as splitting, fungal growth, or premature rotting. 

Pumpkins need more water during the initial growth phase, and less water as the pumpkins start maturing.

What Happens if You Overwater Pumpkins?

If you overwater pumpkins, the leaves may wilt, and the plant may die. Overwatering may also cause the pumpkin to split on the vine or rot in the moist soil. Like most garden vegetables, pumpkins grow best in moist and well-drained soil.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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