Does Mowing Weeds Spread Them? Or Kill them?

Not only do weeds in the lawn make it look untidy, but weeds compete with grass for water and nutrients and will lead to the health of your lawn suffering. If you have an organic garden and do not use chemical herbicides against weeds, you will need some other way to control them. Frequent lawn mowing is the next best solution. 

Mowing the lawn can be an effective way to get rid of weeds. Weed seeds get stuck under the lawnmower and then spread to other areas of the garden, so it is crucial to mow before weeds set seed. Mowing the lawn once a week during summer will encourage the grass to grow densely, suppressing weeds.

However, mowing at the incorrect time or cutting the grass at the wrong height can exacerbate the weed problem. There is a particular method one must adhere to when using a mower to clear the turf of weeds. This article discusses how to prevent spreading weeds with the lawnmower and how one can kill weeds by mowing the lawn. 

Can You Mow Weeds?

The best method of eliminating weeds from the lawn is by using a combination of mowing and the application of herbicide. However, many organic gardeners maintain weed-free lawns without the use of any environmentally harmful chemicals. When done correctly, weekly mowing will control weeds.

Timing is the most critical element when it comes to mowing the lawn to control weed growth. If you mow at the incorrect time, you will only contribute to the problem by spreading weed seeds. One must mow the weeds before they get too large and set seed.

If there are already weeds that have flowered and set seeds growing in your lawn, you will spread the seeds the first time you mow. But if you frequently mow the lawn, cutting the grass at the correct height, you will weaken the weeds over time and allow the grass to smother them. 

Types of Weeds

When tackling a weed-infested lawn, get down to grass level and examine the types of weeds that you are up against. In the same way as our garden plants are annuals or perennials, so are weeds.

Annual weeds are fast-growing and have a short lifespan. They germinate, mature quickly, and set a great number of seeds. Most weeds have seeds that are evolved to be wind-dispersed, so they carry their seeds on tall stems. If you mow these weeds before they set seed, it will weaken the plants and kill them.

Chickweed, nettle, purslane, sorrel, knotweed, crabgrass, spurge, speedwell, pigweed, and lambs’ quarters are examples of annual weeds. 

Perennial weeds are more stubborn. They grow deep root systems, so when you mow them, they have enough energy stored in their roots to re-grow. The only way to permanently get rid of hardy weeds is to manually pull them out or treat them with herbicide. 

Dandelion, bindweed, poison ivy, thistle, ragweed, plantain, dock, ground icy, and quack grass are examples of perennial weeds. 

Prevent Your Lawn Mower from Spreading Weeds

If your grass has not been mowed in a long time and is overrun with weeds, you will inevitably spread the weeds’ seeds when you mow. But there are some ways that you can minimize this:

• Cut the grass at the right height. Set your lawnmower to the correct height. If you cut the grass too short, it damages the lawn, resulting in bare patches of ground where weed seeds can germinate. If you leave the grass to grow at the right height, it can shade the ground, suppressing the weed seeds from germinating. 
• Contain the clippings. Do not use the mulch function on your lawnmower. Use a grass catcher attachment and bag all the weed-contaminated clearings.
• Dispose of the clippings along with your other household refuse. Do not use the clippings as mulch, as this will spread the weeds to your beds!
• Clean the lawnmower after use. Proper cleaning and maintenance of your lawnmower are crucial to prevent the spreading of weeds. When you mow the lawn, moist grass clippings and seeds get stuck underneath the mower. If you do not hose down your mower after using it, the seeds will dry on the lawnmower’s undercarriage. Next time you push it around the garden, the seeds will spread. 

How to Rid Lawn of Weeds by Mowing It

Mowing the lawn to control a weed problem takes time and commitment. The lawn needs to be mowed properly once a week. If you are inconsistent or do not take measures to minimize spreading seeds, this method will not work. Ideally, you should use a combination of frequent mowing, manual weeding, and the application of environmentally friendly herbicides as a last resort if necessary. 

The overall goal is to encourage the grass’ growth and weaken the weeds to suppress them. A good time to tackle the problem is in late fall. Give the lawn a good short cut, pull out big clumps of weeds, apply lawn dressing, and feed it. The grass will grow very slowly over winter, so you will not need to mow it.

In spring, when the grass and the weeds start to grow more rigorously again, mow the lawn weekly, ensuring you set your mower to the correct height each time. The grass itself may not be long enough to cut weekly, but if you cut the weeds that stick out above the grass, you will weaken and eventually kill them. Continue mowing regularly throughout summer.

Wrapping Up

Mowing the lawn weekly in spring and summer is an effective way to control annual weeds. Manually removing hardy weeds or carefully applying doses of herbicide is the only way to get rid of perennial weeds. 

One should take measures not to spread weeds when you mow the lawn. Catch and bag the lawnmower clippings and dispose of them. Do not use weed-infested mulch in your garden. Hose off your lawnmower to clean it each time after mowing. 

It is also important to cut your grass at the correct height. Cutting it too short can damage it, allowing the weeds to outcompete it. Avoid creating bare patches of soil where weed seeds can germinate.