Are Your Squash Leaves Turning Yellow? Here's How to Fix It

<p><a href="">Kevin Trimmer</a> / Getty Images</p>

Kevin Trimmer / Getty Images

There are many different types of squash you can grow in your garden. But no matter which variety you’re tending to, seeing yellow leaves on the plant can be an alarming sight. This raises a few questions: what is making your squash leaves turn yellow, and how worried should you be?

If your squash leaves are turning yellow, it could be for reasons related to watering, pests, disease, or sun level. Here’s how you can tell what might be wrong and how you can save your veggie.

Your Squash Is Underwatered

A common reason why squash leaves turn yellow is because the plant isn’t receiving enough water. Squash is a fast-growing plant that needs a lot of water to thrive. Water allows the squash to function and grow properly, and it helps transport nutrients from the soil into the plant.

To save your thirsty squash plant, make sure it’s getting about one inch of water every week. You might need to increase how much you’re watering the plant if the weather has been especially hot and dry. Water your squash plant whenever the soil’s top layer feels dry to the touch. An automatic irrigation system or hose timer can make the task simple.

Your Squash Is Overwatered

On the other hand, yellow leaves can also be an indicator that your squash plant is overwatered. When the soil is too wet, the roots don’t receive enough oxygen. This leads to damaged—or even dead—roots, which hinders the plant’s ability to flourish.

If your squash plant is suffering from soil that’s too moist, stop watering it and address any drainage issues so the soil has a chance to dry. Monitor the squash plant for a week or two for any changes in health.

To decipher whether your squash plant is overwatered as opposed to underwatered, look at the leaves and soil. Overwatered plants will have yellow, droopy leaves and wet soil. Underwatered squash will have yellow, brittle leaves and dry soil.

The Plant Needs Nutrients

Just as squash plants need lots of water, they also need lots of nutrients. Squash plants need ample nitrogen, phosphorous, and potassium. These nutrients can be found in fertilizers, which you’ll need to work into the soil. Along with yellow leaves, squash plants that lack proper nutrients may also produce smaller-than-desired veggies.

If you suspect your squash leaves are turning yellow due to nutrient deficiency, test your soil’s pH level. This can be done by purchasing a kit, or doing a DIY test with a few common household items. If your soil lacks nitrogen or other nutrients, add it in. Your exact method will depend on the current time of year.

Your Squash Is Diseased

Squash plants are susceptible to a handful of different diseases—many of which can cause yellow leaves. This includes:

  • Alternaria leaf blight

  • Alternaria leaf spot

  • Downy mildew

  • Angular leaf spot

  • Aster yellows

  • Yellow mosaic

  • Cucurbit yellow stunting disorder virus (CYSDV)

  • Stem rot

The causes of these diseases vary, and cures range from using fungicide to completely removing all affected plants.

Insects Have Infested Your Squash

If you’re growing squash, you might come head-to-head with squash vine borers. These are common moths whose larvae burrow into squash vines and feed. This causes the leaves to turn yellow and wilt.

These little pests are difficult to get rid of. You can try preventing them with floating row covers. If they’ve managed to sink their little teeth into your squash vines, use a pesticide to get rid of them or—if you're not squeemish—slice a slit into the affected vine to find the borers, then kill them by hand.

The Squash Plant Needs More Sun

Squash is a full sun plant. This means that the produce needs six to eight hours of sunlight every day to be healthy. Any of these sun-loving crops that are planted in shade simply won’t thrive—and their leaves might turn yellow.

Squash can also be tricky to relocate. If your squash plant is still small, you might be able to replant it somewhere with better sunlight. But it’s important to do your research and first plant your squash in full sun.

Frequently Asked Questions

How do you fix yellow squash leaves?

Fixing squash leaves that are turning yellow depends on why they are turning yellow. You need to address the root cause, which can be anything from watering, sunlight, disease, improper nutrients, and infestations. 

What does an overwatered squash plant look like?

An overwatered squash plant has yellow, wilting leaves that may fall out. The soil may also be wet to the touch.

Should I cut yellow leaves off a squash plant?

Yes, you can remove yellow leaves from your squash plant. Just be sure to only remove the leaf and not make any cuts to the vine, which can harm your plant. Often, yellow leaves might break off easily with a bit of pressure.

Read Next: Yellow Leaves on Tomato Plants? 8 Causes and How to Fix Them

Read the original article on The Spruce.