Spring lawn care in the UK: what to do and when

Spring lawn care is five jobs in a fixed order: first cut, moss and weeds, feed if the lawn needs it, seed when the soil is warm enough, and only then the regular mowing routine. The order matters more than the dates, because every job depends on the one before it and on how fast the grass is actually growing. March one year is not March the next.

The month table below is the map. The sections under it explain why the jobs sit where they do, and what to do in a spring that runs early or late.

The spring jobs, month by month

Month	Do this	Avoid
March	First cut, once growth has clearly started. Light and high, about 40mm or the mower’s highest setting. Rake out moss. Soil test.	Cutting short. Heavy scarifying.
April	Mow weekly as growth picks up. Remove weeds by hand. Feed only once growth is well underway, and only if the lawn needs it.	Feeding cold, wet ground. Sowing seed into cold soil.
May	Peak growth. Mow weekly or more. Lower the height gradually. Remove weeds by hand.	Cutting more than a third of the leaf at once. Heavy feeding into heat.

If you do use a weedkiller or mosskiller, choose an HSE-approved product and follow the label exactly. For most spring lawns, hand weeding and a rake do the job.

March: start light

The first cut of the year is a tidy-up. Wait until growth has clearly started, then cut lightly and high, about 40mm or the mower’s highest setting. The trigger is growth, not the date. A lawn cut hard in March on a cold year loses leaf area it cannot replace yet, and the grass sits thin and vulnerable until the weather catches up.

March is also the month for two jobs that are easier before the lawn gets long. Rake out moss while it is visible and the sward is short; the moss guide covers how far to go. And if you have never tested the soil, do it now, before you buy anything to put on it. A soil test tells you whether the lawn needs what spring feeding is about to sell you.

What not to do in March: cut short, and scarify hard. Deep scarifying is autumn work because the lawn needs about a month of active growth to close over again afterwards. A light rake for moss is fine. The full reasoning is in when to scarify a lawn in the UK.

April: let the lawn get ahead

By April most UK lawns are growing steadily, and mowing becomes weekly. Keep the height moderate rather than dropping to summer settings in one go, and keep the blade sharp; a torn leaf browns the tips and costs the plant photosynthesis it needs right now.

April is when people reach for the feed. The RHS position is that most lawns will grow perfectly well without being fed, and that feeding is worth doing only once growth is well underway and only if the lawn actually needs it. A lawn that is growing, green and dense needs nothing. A lawn that is pale and thin may benefit. Soluble nitrogen applied before growth starts largely washes through the soil and out of the root zone, and feeding hard into cold, wet conditions pushes soft, lush growth that is more susceptible to fusarium patch. It is a risk, not a certainty, but it is the reason “wait until growth is well underway” is the rule. The full version, including what to put down if you do feed, is in when to apply spring lawn feed.

Weeds show themselves in April once the grass is growing. Remove them by hand while they are small. If you do use a weedkiller, choose an HSE-approved product and follow the label exactly; most spring weeds do not need one.

Seeding and overseeding can start in spring, though autumn is the better window for established lawns. The gate is soil temperature: grass seed germinates on species thresholds rather than on a date, and sowing into cold soil is the main reason spring seed fails to appear. How long grass seed takes to germinate has the thresholds, and overseeding timing has the window.

May: the growing month

May is when the lawn does its own work. Growth is at its fastest, the mower is out weekly or more, and the job shifts from starting the lawn to keeping up with it.

Lower the cutting height gradually through May, a step at a time, rather than in one cut. Never take off more than a third of the leaf in one cut: the RHS mowing guide’s rule, and the one that keeps a lawn thick enough to shade out weeds. This is also where the mowing height you choose starts to matter for moss and weeds later in the year; how short to cut grass is the article that works through the trade-offs when it lands.

Keep removing weeds by hand as they appear. Heavy feeding into heat is on the avoid list: lush growth stressed by a dry spell is the fastest route to a brown lawn in June.

What actually sets the timing each year

Everything in the table is a default, and three things override it.

Soil temperature is the main one. Meaningful growth begins at about 6C soil temperature (Teagasc puts the onset of grass growth there; sources give a band of about 5 to 6C, and 6C is the parameter our model uses, measured at 6cm; see /method). When the soil crosses it early, the whole table shifts forward; when it crosses it late, so does the work. The variability is real: the JNCC’s Spring Index shows UK spring timing shifting by days to weeks between years.

The second is moisture. A waterlogged March is not a mowing month whatever the temperature says, and a dry April changes how the lawn responds to feed.

The third is growth stage, which is what you can actually see. Grass that is growing is ready for the next job. Grass that is not is not, whatever the month says. This is the argument in full in why calendar lawn advice is wrong, and it is why our spring feed timing article never gives a date without the condition attached.

How mowdar fits

The table gives you the jobs. What it cannot give you is where your lawn is right now. For any UK or Ireland location, mowdar models soil temperature at 6cm and growth potential on the PACE Turf framework, and turns them into a 10-day mow forecast with a confidence figure from a 94-run ensemble. In a spring that runs early or late, that is the difference between following the table and knowing which year you are in. The mow forecast is the starting point.

FAQ

When should I start mowing the lawn in spring? When growth has clearly started, and lightly at first: about 40mm or the mower’s highest setting. The grass being long enough to need a cut is the signal. The month is a rough guide, not the trigger.

Should I feed my lawn in early spring? Only once growth is well underway, and only if the lawn needs it. Pale, thin grass may benefit; dense green grass will not. Feed applied before growth starts mostly leaches below the root zone. The full timing logic is in when to apply spring lawn feed.

Is spring a good time to scarify or aerate? Light work only. Raking out moss and surface debris suits spring, and a light scarify can help a lawn that missed autumn. Deep thatch removal and aeration are autumn jobs, because the lawn needs roughly a month of active growth to recover and spring gives it less season to do it in. See when to scarify a lawn in the UK.

When can I sow grass seed in spring? When soil temperature reaches the germination threshold for your seed mixture, which for most UK mixtures means waiting until the soil is genuinely warming rather than sowing on the first mild week. The species thresholds are in how long grass seed takes to germinate, and autumn remains the easier window for overseeding.

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Spring lawn care is mostly timing, and timing is mostly local. The growth window for your location shows what the soil is doing now, and the mow forecast shows the fortnight ahead.