If you must mow your lawn after a frost, the best practices are to ensure that your lawn does not have a lot of moisture from snow or ice and make sure to not mow the lawn when the temperatures are below 40 degrees Fahrenheit.
Once your grass has come out of its dormant state, you may be wondering when you should start cutting it again. Generally speaking, if it is below 50 degrees Fahrenheit, it is still considered to be too cold to mow your lawn. The ideal temperatures to mow are between 50 to 80 degrees Fahrenheit.
Cut your lawn to possibly the shortest height you have all season. The ideal height is around 2 1/2 inches. Cut it too low and the grass might not be long enough to photosynthesize and provide nutrients to the roots. Too high and the frost might become matted after a snowfall.
Plan to mow your lawn during the evening hours, after the heat of the day has passed. The temperature should be between 40°F and 80°F.
Mowing right before frost is bad because your grass blades will need help to heal themselves. They will undergo additional stress because of the harsh weather conditions. All grass types become dormant at sub-zero temperatures that occur during frost.
You should never mow your lawn when temperatures are below freezing point or consistently below 40 degrees Fahrenheit. To protect your grass, mow your lawn in warmer conditions. It's best to wait until temperatures remain steady at above 40 degrees for about 7 days or more.
Grass can grow in the winter provided the conditions are right. The average minimum temperature required for grass growth and seed germination is between 46-50 degrees Fahrenheit, and some species can grow in temperatures as low as 40 degrees Fahrenheit.
Cool-season grasses should typically be cut to about 3 to 4 inches high. Warm-season grasses should typically be cut to about 2 to 2 ½ inches high. The common cool-season grasses include fine and tall fescue grass, Kentucky bluegrass, and perennial ryegrass.
Grass needs the benefit of the day to dry and heal before dusk settles. Since mowing your grass in the early morning can damage it and mowing it during the early afternoon can burn it because of all the high temperatures, the ideal time is mid-morning.
Is it bad to cut grass in a heat wave? Yes, it can be. The heat leaves your grass 'stressed' and cutting it too often or too short can make this worse. If you do mow, try doing so a day or so after it rains, when your grass is likely to be happier.
The best height to cut grass in the fall
Focus on striking the right balance in fall so your lawn's ready for winter. Shorten your cool season grass to about 2.5 inches before the first frost in winter. Mow warm-season grasses to 1.5 or 2 inches in fall.
The theory that cutting short lengthens the time between cuts also doesn't hold up. Grass grows faster after it's been cut short as it tries to rebuild itself to its genetic norm. A good in-season height for most turfgrasses is 2½ to 3 inches — typically the highest setting on mowers.
Ideal grass length
The mowing height range for most grasses is between 1.5 and 3 inches. In general, for most lawns 2 to 2.5 inches is optimum because if you are mowing at 3 inches, your lawn may grow to 5 or 6 inches before you mow it again.
Mowing every two weeks — instead of weekly — and not dousing grass with chemical herbicides and fertilizers, helps the environment and supports the health of bees, which are among the world's most important pollinators.
However, be mindful that mowing too close to nightfall (between 6 and 8 p.m.) will not give your grass enough time to recover, making your lawn more susceptible to fungus and turf disease. It's recommended to avoid cutting your grass in the early morning and midday.
If your grass is too long, it's at risk for disease. The ideal grass height for winter is between 2 inches and 2.5 inches. This keeps grass short enough to resist disease spread, but not so short that it becomes overly stressed by cold temperatures.
'As long as your blades are sharpened, and the grass isn't not soaking wet, mowing in the early morning dew is totally fine,' says Douglas Dedrick.
So, should you water after mowing? The simple answer is yes, but only if your grass needs the moisture. If you've had a rainy week and the grass isn't showing footprints or other signs of dehydration, you can probably put off watering for a bit longer.
Is mowing before or after rain better? It is always better to mow before rain if possible. If your grass is dry, but you see rain on the way, it is a good idea to mow the yard before the rain arrives. Otherwise, the next best time to mow is when your grass has completely dried after rainfall.
Mowing actually helps make your grass grow thicker because the tip of each blade contains hormones that suppress horizontal growth. When you cut the lawn, you remove these tips allowing the grass to spread and grow thicker near the roots.
Lawn clippings usually do not need to be bagged. Recycling lawn clippings can reduce your fertilizer needs and improve your soil. Recycling clippings to the lawn does not contribute to thatch. If you must remove clippings, they can be composted or used as mulch.
A mowing height between 2.5 to 3 inches is best for most of the season, except during summer stresses when the lawn mowing height should be raised one-half inch to mow at 3 to 3.5 inches. Raising the mowing height provides more insulation from summer heat and reduces water loss from your soil.
Daytime temperatures around 60 to 75 degrees Fahrenheit typically mean the soil temperature is between 50 and 65 degrees and perfect for seed germination. If the soil temperature is much lower than 50 degrees, however, the seeds will lay dormant and not germinate.
If the daytime temperature is below 60°F then soil temperature is below 50°F, making it too cold; if there is frost or still a danger of frost, then it's too cold. If it's too cold, the grass seeds will likely rot.
Temperature – Soil temperature plays a major role in the growth of grass. When soil temperatures reach 50 degrees, grass will start to come out of dormancy and grow. Between 50 and 75 degrees, cool season grasses will grow most vigorously.