When to Mow Lawn

When to Mow Lawn

Mowing the lawn might seem like a simple task, but timing plays a major role in how your grass looks and performs. Cutting too early, too late, or too often can stress the grass, weaken the roots and leave your lawn open to pests and disease. The key to effective mowing is to match your cutting schedule to the growth pattern of the grass and the conditions of the season.

Understanding Grass Growth

Grass doesn’t grow at the same rate year-round. In the UK, it begins to grow actively when soil temperatures rise above around eight degrees Celsius, usually in early to mid-spring. Growth peaks in late spring and early summer, slows slightly in midsummer during dry spells, and then picks up again in early autumn before going dormant in winter.

Your mowing habits need to adjust as the grass changes. In spring and autumn, it grows quickly and needs regular cutting. In high summer or cold months, it barely grows at all and may not need mowing for weeks.

The First Cut of the Season

The first mow of the year usually happens in March or April, depending on the weather. You should wait until the ground is firm and dry and the grass is actively growing. For this first cut, raise the blade height to avoid scalping and only trim the tips. This wakes the grass up and encourages new shoots without putting it under stress.

After that, as growth picks up, you can gradually lower the blades to your preferred mowing height. Cutting too low, especially early on, weakens the grass and exposes the soil, which invites weeds and moss.

How Often to Mow

During the peak growing season, from late spring through summeryou may need to mow once a week, or even twice weekly on high-performance lawns. The golden rule is to never cut more than one-third of the grass blade in a single mow. Removing too much at once shocks the grass and affects its ability to photosynthesise and stay healthy.

In dry or hot conditions, reduce the frequency of mowing and raise the cutting height. Longer grass retains more moisture and shades the roots, which helps the lawn resist drought stress.

In autumn, as growth slows, cut less frequently and raise the blade gradually until the final mow of the year. The last cut usually takes place in late October or early November, just before grass goes dormant.

Mowing in Winter

Grass can still grow a little in winter during mild spells, but it’s usually not enough to warrant mowing. If you do need to cut in winter, say during a warm December weekmake sure the ground is firm and dry, and only take the tops off. Never mow if the grass is frosty or waterlogged, as this will damage both the turf and your mower.

The Best Time of Day to Mow

The ideal time to mow is mid-morning or early evening on a dry day. Early morning dew can clog the mower and cause clumping, while mowing in the heat of the day stresses the grass. Evening mowing avoids heat stress and gives the lawn overnight to recover. Just avoid mowing too late if there's overnight moisture, which can increase the risk of fungal problems.

Watch the Weather – Not Just the Calendar

Mowing by date alone isn’t reliable. In early spring, cold snaps can delay growth even into April, while mild winters might prompt earlier cuts. The key is soil temperature. Grass usually starts growing when soil warms to around 8–10°C, not just when air feels mild. Use a soil thermometer or observe when the grass visibly thickens and lengthens.

The One-Third Rule Matters Year-Round

No matter the season, the one-third rule should always guide mowing. Cutting off more than a third of the grass blade in one go shocks the plant, slows recovery, and leaves it vulnerable to sunburn, scalping or fungal infection. Even if the lawn looks overgrown, lower the blade gradually over several mows.

Cutting Height Shouldn’t Stay the Same

Lawn health improves when cutting height is adjusted throughout the year. Early spring and late autumn cuts should be slightly higher to protect tender roots. In peak summer, raise the blade to help grass retain moisture and shade the soil. Only lower it to your preferred finished height once growth is steady and the lawn is lush.

Damp Grass = Trouble

Mowing wet grass may seem tempting in a packed week, but it leads to clumping, scalping, mower damage, and uneven cuts. If your mower’s wheels leave muddy marks or the cut looks ragged, it’s too wet to mow. Wait for drier conditions to avoid damaging both turf and equipment.

Frequent Mowing Builds Lawn Density

Mowing encourages side shoot development in grass. That means regular cutting actually helps thicken the lawn. This is particularly useful when overseeding or trying to outcompete weeds. Letting the lawn grow long between cuts does the opposite, it weakens the grass, opens the canopy, and allows weeds and moss to move in.

Don’t Bag Every Time

While collecting clippings gives a clean finish, leaving clippings on the lawn occasionally, known as mulchingcan return nutrients and moisture to the soil. Only do this when the grass is dry and the clippings are fine enough not to smother the turf. It’s particularly beneficial during spring and early summer.

Avoid Mowing After Feeding

After applying fertiliser, wait at least 3 to 4 days before mowing, and make sure the lawn has been watered or rained on. This ensures nutrients reach the roots properly before any physical disturbance. Mowing too soon can remove nutrients and disrupt absorption.

Edge Care Counts Too

It’s easy to overlook lawn edges, but keeping them trimmed improves airflow, defines the lawn’s appearance and prevents encroachment of grass into beds and paths. Edge trimming is best done after mowing, while the grass is evenly cut and easier to shape.

Final Word

Knowing when to mow your lawn is about more than keeping it tidy. It’s about working with the rhythm of the seasons to support strong, healthy grass that stands up to weather, foot traffic and pests. By adjusting your mowing habits to the time of year, the condition of the lawn and the weather on the day, you can keep your lawn in top shape from the first cut of spring to the last tidy trim in autumn.