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Why Are My Squash Plant Stems Splitting

Squash is a pleasant and versatile fruit that many gardeners are learning to grow. Whether it’s a spaghetti squash turned into noodles or a butternut squash chopped and roasted, there are plenty of ways to turn squash into a delicious bite. If you have the ability to grow your own squash, take advantage of it. Remember, not all fruits and vegetables turn out great every time they are grown. Squash, like any crop, has common growing issues. Maybe you’ve noticed a problem with your stems and are concerned with what’s happening. Specifically, you may wonder, Why are my squash plant stems splitting?

Squash stems can easily be split and ruined because of harsh weather. A sudden wind gust or heavy rainfall may bend a squash plant stem to breakage. There are also pests such as the squash borer that can feed off of squash plant stems and cause them to weaken and eventually split. Large squash fruit may also be too big for the stems to support, causing splitting.

Keep reading to learn all about squash plants, the reasons their stems may be splitting, and ways to prevent them from doing so. 

What Is Stem Splitting?

Stem splitting is the unfortunate process of a stem that has cut itself in half and exposed its inside. The stem can’t hold nutrients well anymore; therefore, it will dry out and eventually die. This can negatively affect the squash that is growing on it and possibly halt its growth and ripening.

Squash plant stems are typically tall and very hollow, making them more prone to splitting open. Many gardeners discover that their squash plant stems will split overnight or within 24 hours. It can happen quickly and may take a while to notice.

It’s possible to save a stem after it has split, but it’s not a guarantee that it won’t die. It’s better to prevent squash plant stems from splitting in the first place. 

Simple Ways To Prevent Your Squash Stems From Splitting

  • Support your squash plants with a tomato cage or steaks. Sometimes squash can be too heavy for its stems to bear. Extra support will take weight directly off the squash plant stems and allow them to strengthen and transport nutrients effectively. 
  • If you notice a split beginning to develop, grab some extra soil and build it up around the stem until the split is covered. The stem can better hold its moisture and nutrients with a protective layer of soil around it. It will help heal the stem and prevent the split from getting too large and eventually killing the squash. 

What Is A Squash Vine Borer?

A squash vine borer is a moth with the same body and mannerisms as a wasp. They are typically black and red. Vine borers use the stems of squash plants to home their families. It may sound odd, but it’s true.

They lay their eggs at the bottom of the stem, which eventually hatches into newborn vine borers. Those babies occupy the stem as a new home and cause a blockage. The blockage will prevent water and nutrients from coming through the stem, causing it to eventually split open.

Squash vine borers can also create small cracks in the stem to access them. Too many access points will turn into one large split. Overall, squash vine borers are the main pest to look out for when growing squash plants.

Prevention and Removal Of Squash Vine Borers


After planting your seedlings into the ground, cover them with a transparent seedling cover. You can find these online or at your local home and garden store. Once the seedlings begin to develop flowers, remove the covers to allow easy access for pollination.

If you notice an exposed stem, cover it with tin foil or a plant-friendly material to keep the vine borers from accessing the stems. Preventing the vine borers from accessing your squash plant stems is easier than letting them enter in the first place and having to remove them. 


Vine borers leave behind a residue called frass. It is a sawdust-like material that is orange in color. If you notice frass falling out of certain areas of your squash stems, you can assume you have a vine borer infestation. You will notice small splits in the stem where frass is collecting.

Use a sterilized needle or razor to make a tiny vertical slit exactly where the frass splits have developed.

After you make a slit, pull out the vine borer larvae with sterilized tweezers. Lastly, bury the openings in good soil so the stem can heal and be better supported. If you are lucky, new roots may develop under the soil cover. This is the most natural and effective method for removing vine borer larvae without using pesticides or harmful chemicals. 


Overall, it is very harmful to a squash plant if its stems split open. Once cracked, their insides are revealed and typically dry out. The stems won’t be able to transport nutrients the way they are made to. This will yield a small squash harvest if there’s even one.

Split stems usually cause the plants to die off. Examine and study your squash plants often. If you notice even a slight split in the stem, choose one of the above methods to try and save them. Try supporting your squash plants with stakes or cages to protect them from harsh wind.

Also, don’t forget to cover your seedlings and stems properly to deter squash vine borers from entering your squash plant stems. With this knowledge, you should have the tools to protect your squash plant stems and prevent them from suffering severe damage. 

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