How to Keep Weeds Out of Sweet Corn ( 5 Simple Tips you can Implement Today)

Have you ever planted corn only to realize that the weeds came up with the corn?

Handling weeds when growing corn is not only frustrating, but it can be challenging, mostly if you failed to manage weeds that grow at the onset. Invasive weeds compete with the corn for moisture and nitrogen. The result is a reduced sprout survival rate and less of a harvest than expected.

Ensuring that you keep weeds out of corn is essential as you don’t want them interfering with your corn.

Here are tips on how to keep weeds out of sweet corn.

  • Get a Weed Killer Before Planting

Corn tends to grow with invasive grasses and weeds in early spring, fall, or winter. However, if you’re planning on growing corn on a weed-free patch of land, you need to take the necessary steps to ensure that your plants thrive.

A weed control solution that eliminates grasses and weeds down to the roots is a great option. You can create a natural weed control solution using a vinegar-based weed killer. A pre-emergent herbicide can also be used to prevent weeds from sprouting.

When using a weed control solution, make sure to use it at least three weeks before planting the sweet corn. Spray the entire space with the solution and wait for a week for the weeds to die.

Remove the dead weeds and water the land as you would during the growing season. Repeat the weed killer application. If you notice extra weeds cropping up, reapply the weed killer solution. Once you’re done eradicating the weeds, you can plant your corn.

  • Cover the Land With Black Plastic

Another effective way to grow corn and not deal with stubborn weeds is to use black plastic to cover the round. The method works for corn planted in raised beds or smaller corn patches.

The plastic blocks moisture and sunlight from getting to the weeds and kills them. However, you should do this two months before planting corn. Secure the plastic with rocks to avoid it being blown away.

Removing the plastic will reveal a pile of dead vegetation. Rake the weeks away, and prepare your land for planting.  It’s recommended to spread an inch layer of compost over your land patch without tilling. You can plant immediately after placing the compost. Black plastic is an organic way of killing weeds.

  • Learn the Right Watering Techniques

Watering your sweet corn with soaker hoses is one way to have weed-free land. You can use a drip system if you don’t have soaker hoses.

Although overhead sprinkling is a standard watering method, it gets the whole land wet, including the weeks looking to grow.

When watering, you should use the soaker hoses for at least 4 hours every four to six days. That will encourage profound root growth.  Choosing to water for a few hours for some days only leads to shallow stalks and roots that tend to topple when there’s a strong wind.

If you doubt that you may be overwatering or underwatering your corn, you can dig an inch down. Dry soil shows that the corn needs water, but if the land is moist, it shows that the corn has enough water and can wait for a day or two before being watered.

  • Controlling Weeds After Planting

You may notice little weed growth as you water the plants. Unfortunately, these weeds tend to create a harsh growing environment for your crop. Herbicides like glyphosate and Cartefenrazone can help control established and newly-emerging weeds after planting your sweet corn. Note that you cannot harvest the corn until 45 days when using these herbicides.

Non-selective herbicides like glyphosates are only effective when applied to the corn’s stems or foliage. You should be careful when using these herbicides as any slight drop could kill the other crops around your patch. Always use the shield on the end of your spray to prevent drift.

Applying the herbicide when it’s not windy also eliminates the possibility of drift. You can also put the herbicide to the target weeds using an applicator, a wick application method.

Implementing organic weed control is an alternative to chemical herbicides. Most garden centers stock these organic herbicides that contain clove oil, citric acid, cinnamon oil, or vinegar.

You can also create a homemade weed killer by using undiluted vinegar.  Vinegar burns these weeds, and they end up wilting and dying. Nonetheless, note that you may need to repeat this process to be effective.

  • Use Hand Weeding Techniques

You can also keep weeds out of sweet corn by hand, pulling the ones with gloves that grow close to young sweet corn.  If you notice that weeds are growing between cornrows, you can use a rake or a hoe to kill them.

Handling weeds that grow between cornrows in vast areas can be daunting. A tiller can help you get rid of these weeds.

Tips to Kill Weeds Without Harming Your Sweet Corn

Weeds have a habit of cropping up during the early growth stages of sweet corn. The problem is that these weeds can choke young corn. Fortunately, you can kill weeds without destroying the corn.

Implementing selective weed killing after planting will require a broadleaf weed killer containing 2,4 D on the weeds. Ensure that you apply little herbicide by using a spray can. For best results, spray when temperatures are between 40-90 degrees.

Experts recommend spraying the herbicide when it’s not rainy or windy. These conditions can impact the herbicide’s effectiveness. Moreover, you don’t want the herbicide blowing onto your corn. Avoid applying the herbicide when corn gets to 3ft tall or higher.


Controlling weeds early is the best way to ensure that your sweet corn makes the best nitrogen use. Killing weeds before planting corn also makes it simpler to spot-treat weeds or use hand-weeding methods. We understand how frustrating weed control can be. Using the above tips will help you keep weeds out of sweet corn before the planting, during the planting session, and after planting.

Sources and References

Weed Control in Corn –

5 Tips For Corn Weed Management –

Weed Management in Corn –

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