When To Stop Mowing Lawns in the Fall

The fall season brings various yard work chores, with raking leaves often a top priority. Now probably you are searching for how to stop mowing lawn in the fall. While leaves pile up and planting beds need cleaning, mowing the lawn may seem unusual during this time. However, in regions with cool-season turf, fall is when grass grows rapidly, thanks to a mix of cold temperatures and consistent rain. On the other hand, warm-season turf often goes dormant in areas where frost sets in during autumn.

Why Mowing Your Lawn Is Important

Mowing the lawn isn’t just about keeping it visually appealing or creating a neat appearance. Regular and timely mowing maintains the grass at an optimal height, which supports nutrient absorption and promotes strong root development. It also helps prevent diseases and reduces the risk of insect infestations.

Moreover, frequent mowing plays a significant role in weed control, ensuring weeds don’t overrun the lawn during spring and summer. But does mowing remain necessary when temperatures begin to drop? What is the ideal timeframe for this task?

Why You Should Stop Mowing Your Lawn

Experts recommend maintaining lawns at a 2.5 to 3-inch height throughout the year. However, as lawns and plants grow more slowly in the fall when temperatures range from 70°F to 50°F, most lawn care specialists agree that mowing is unnecessary.

Why Is the Final Cut of the Year Crucial?

The final mowing of the year is more important than many homeowners realize. It can significantly affect how well turf resists disease during the winter and how healthy it will be in spring. When preparing for this last cut, adjust your mower blade to the correct height:

• Kentucky bluegrass and ryegrass: 1.5 inches
• Tall Fescue grass: 2 inches

The Ideal Timeline

Determining the best timeline for your lawn’s final mowing depends on its growth and local climate. Experts suggest mowing until grass growth noticeably slows. This happens in late October or November for many regions when temperatures drop below 50°F. In some climates, mowing may continue till early December.

Regular mowing before temperatures drop can reduce spring damage caused by winter mold and voles. However, cutting grass too short may stress it, leading to more harm than damage from pests or disease.

For lawns typically maintained at 2.5 to 3 inches, keeping them at this height is advisable. Experts suggest trimming taller grass down to 3 inches before winter. This recommendation varies by location, with the ideal time ranging from late October to early December.

As temperatures drop, lawns enter dormancy. This is a natural process, so there is no need to worry. Your grass will resume growth when air and soil temperatures rise again in spring.

Mowing Cool-Season Grass

If you have snow in your winter landscape, your turf is likely one of the cool-season grass types. Fine fescue, perennial ryegrass, and Kentucky bluegrass are all cool-season grasses that thrive in the colder temperatures of fall and spring. It’s not unusual for these grasses to fall into dormancy in the summer, turning brown and crispy. They typically come back to life in the autumn when humidity levels and cooler temperatures return.

When temperatures drop in the fall, the soil temperature usually remains ideal for grass growth in cool-season grasses. If rainfall is consistent and the soil stays warm, the turf will grow quickly and require regular mowing.

Cut cool-season grass once it has stopped growing. Ensure the season’s final mow leaves the grass 3 to 4 inches high. Keeping the grass slightly shorter is recommended rather than leaving it too long. Long grass can be more prone to lawn diseases in the spring because it does not dry quickly. Soggy, moist grass and moderate temperatures create the perfect conditions for establishing diseases.

Mowing Warm-Season Grass

Warm-season grasses, such as Bermudagrass, St. Augustinegrass, Zoysiagrass, and centipedegrass, slow their growth significantly during late fall. Due to this reduction in growth, you can expect to mow less frequently. Help warm-season grasses adjust to changes in growing conditions by raising the mower deck by about 1/2 inch. 

For example, if your lawn is set at 2 inches, raise the deck to 2 1/2 inches in late fall. This increased cutting height gives the grass more surface area to absorb sunlight.

Mowing warm-season grasses during late autumn and winter is typically more about controlling weeds than trimming the grass. Weeds like annual bluegrass, burweed, and chickweed are active during the warmer months when grasses are either dormant or growing slowly. Pre-emergent herbicides applied in September and October are the best method to manage these weeds. Late autumn and winter mowing can help control them if they reappear after the herbicide application window has closed.

Mowing Cool-Season Grass

If snow is part of your winter landscape, your lawn is likely made up of cool-season grasses. These include Kentucky bluegrass, fine fescue, and perennial ryegrass, which thrive in cooler temperatures during the fall and spring. It’s common for these grasses to go dormant during the summer, turning brown and crispy, but they typically revive in the fall when the weather becomes cooler and more humid.

As temperatures drop in the fall, the soil’s temperature often remains ideal for cool-season grass growth. With regular rainfall and warm soil, the turf will continue growing quickly and require frequent mowing.

Once the grass stops growing, ensure the final mowing of the season leaves the grass at 3 to 4 inches high. Keeping the grass slightly shorter rather than leaving it long is best. Longer grass is more vulnerable to lawn diseases in the spring because it does not dry out quickly. Wet, damp grass in mild temperatures is ideal for developing diseases.

Why Cutting Grass Before Winter Is Important:

• Long grass can stretch and roll over in the snow. When grass becomes matted, it creates a perfect environment for winter fungal diseases and snow mold.
• The matted grass may suffocate your lawn in the spring, making it harder to recover from the winter.
• Shorter grass is more rigid and better able to withstand snow and ice damage.

In addition to mowing, it’s crucial to clear any debris, such as leaves and twigs, or mulch them into the lawn before winter sets in. Leaving debris on the lawn during the winter can suffocate the grass and encourage the development of fungal diseases.

Fall Mowing Plan

Prepare your lawn for winter by following a fall mowing plan. In areas with snowfall, the goal of the final mowing is to cut the grass as short as possible without scalping it. For most turf types, this is typically around 2 inches. Gradually reduce the mower’s height until the grass is shorter. Each time you mow, remove only one-third of the total blade length. If the grass grows quickly, you may need to mow twice weekly to achieve the desired height.

Mow While Grass Is Growing

If your lawn is still growing, continue mowing. It will develop long after many annual and perennial plants have gone dormant or died from frost in the fall. While it may be tempting to store the mower for the winter after composting the perennials and clearing out the vegetable garden, continue mowing your grass as long as it grows.

Follow the One-Third Rule

Let the height of your grass, not the time of year, determine when to cut it. It’s best not to remove more than one-third of the blade when mowing. 

This is called the “one-third rule.” If your mower is set to 3 inches, mow the grass before it reaches 4.5 inches. By cutting only one-third of the blade each time, you encourage healthier growth, improve root development, and reduce the risk of thatch.

If the grass never reaches the ideal height, it’s no longer growing. The ideal mowing height depends on the grass type. Be sure to know the ideal height for your specific turf.

What to Do About Leaves

You can mow the lawn while leaves are on it or use a leaf vacuum to remove them. Leaves are rich in nutrients that benefit the soil and promote a healthy lawn. Mowing the leaves into small pieces helps them break down faster and get absorbed by the turf. If raking leaves from landscape beds, remember to mow over them too.

For best results, mow the leaves when dry and raise the mower deck by a couple of inches to handle the thicker layer of leaves.

FAQs

What time of the year is it safe to cut grass?

A good rule of thumb is to keep mowing as the grass grows. Cool-season grasses tend to keep growing into late October or November. While mowing frequency decreases as temperatures drop, keeping track of your lawn’s growth patterns is important to ensure it’s mowed regularly before winter arrives.

When do I need to stop cutting my lawn before the start of winter?

The ideal time to stop mowing is when the grass stops growing. Sometimes, depending on weather conditions, you may need to continue mowing leaves until December. If snow isn’t expected to last, it’s not a signal to stop mowing. The decision depends on the grass’s growth and the leaves’ condition.

When do I need to stop mowing?

If the weather has been very dry and temperatures are consistently below 50°F, it’s time to stop mowing. Without proper humidity and cool temperatures, grass will not grow and won’t need cutting. Depending on your local climate, this period typically falls between late October and early December.

Should I let my lawn grow longer in the fall?

Keeping your lawn at a height of 2.5 to 3 inches is advisable. Cutting grass too short can prevent it from getting enough sunlight and may damage the crown of the grass. Allowing it to grow longer increases the risk of winter-related rot, especially when frost or snow is present.

Can I mow my lawn after the first frost?

You can mow after the first frost as long as the grass grows. However, avoid cutting too short, as the cold temperatures may weaken the grass. Always ensure that the grass reaches the desired length before mowing.