When to Mow Your Lawn for the First Time in Spring: Forsythia Shows the Way

As the days lengthen and the sun returns, the grass can look patchy and dull – and it is tempting to get the mower out at last. However, mowing the lawn too soon does more harm than good. An unassuming shrub with bright yellow flowers provides a remarkably reliable clue to the right time.

Why the timing of the first spring mow matters so much

After winter, much of the lawn’s activity takes place out of sight. The blades may appear weak, but below ground the roots are rebuilding their energy reserves and forming new branches.

Mowing prematurely forces the grass to divert that valuable energy into replacing lost blade length. As a result, the lawn becomes more vulnerable to dry spells, fungal diseases and bare patches. It may look tidier in the short term, but over the season it will be less dense and a paler green.

The first mow after winter determines whether your lawn remains dense, rich green and hard-wearing in summer – or quickly becomes patchy and susceptible.

Specialists offer a clear guideline: temperatures should no longer fall below around 4°C for several nights in succession. Grass only begins growing noticeably again once the soil reaches approximately 6°C. Below that level, using the lawnmower mainly achieves one thing: wasted time and unnecessary stress for the lawn.

Forsythia’s yellow flowers: the natural signal to begin

Rather than relying solely on calendar dates, many experienced gardeners use a straightforward indicator: the forsythia, an ornamental shrub with vivid yellow flowers. It blooms before its leaves emerge, making it especially responsive to weather conditions.

When the shrub’s branches are glowing yellow, it indicates that vegetation is stirring and temperatures are settling at a more stable level. This is usually a good time to schedule the first mow – provided the weather cooperates.

Before the first cut, a quick maintenance session is worthwhile:

• Rake away leaves, small branches and thatch.
• Carefully loosen clearly visible patches of moss.
• Set the lawnmower to a high cutting height.
• Use sharp blades only, so that the grass is cut cleanly.

This leaves a tidy surface without damaging the turf or shredding the blades.

Four simple signs that the lawn is ready

If you are unsure, use these easy checks as a guide:

• A forsythia shrub in your garden or neighbourhood is in full bloom.
• No night frosts have been forecast for several days, and the nights are noticeably milder.
• The ground is not muddy, can be walked on without leaving deep marks, and the grass is dry.
• The blades look flexible and bright green, with clearly visible new growth in height.

When these signs coincide, it is time for the first mow – but do it gradually. Never remove more than around one third of the blade length at once. For instance, if the grass is 10 cm high, the first cut should reduce it to no less than about 7 cm.

Protect flower bulbs rather than mowing them down

In spring, leaves from daffodils, crocuses and tulips often still protrude through the lawn. Where possible, leave them in place until they die back naturally. More careful mowing helps:

• Deliberately mow around clumps of bulb foliage.
• If necessary, leave small islands uncut and mow them later.
• Mow at a slower pace so you can steer around plants more easily.

This preserves the bulbs’ reserves and ensures that the spring flowers return reliably the following year.

Why not every square metre of lawn needs to be short

Alongside the debate over the best mowing time, a trend towards less strictly maintained lawns has grown in recent years. The central idea is to keep only paths and usable areas short, while allowing the remaining sections to grow in places. It was prompted by an initiative encouraging people to mow as little as possible in May.

Many garden owners therefore cut only narrow routes as paths, leaving the strips or islands between them to grow naturally. In practice, this brings:

• considerably less mowing work
• more flowers among the grass
• more frequent visits from bees, bumblebees and butterflies
• a more varied garden appearance

Those who let parts of the lawn grow give insects food and themselves more time – without the garden immediately looking neglected.

One garden owner responsible for around 500 square metres, for example, says that they now keep only paths and seating areas short. The rest is allowed to grow taller, providing flowers for pollinators while still looking orderly if the edges are kept neat.

Dandelion flowers as energy bars for pollinators

Dandelion flowers are particularly underestimated. While many people remove them almost automatically, specialists regard them as a valuable food source for wild bees and other pollinators, especially in early spring when little else is flowering.

A respected gardening association therefore recommends deliberately tolerating some plants in the lawn instead of removing every yellow flower immediately. Studies show that countless insect species depend on flowers, while a large proportion of native wild plants reliably produce seed only through insect pollination.

At the same time, researchers have recorded a decline in many insect populations for years. The change is gradual but consistent. Against this background, taller, flower-rich parts of gardens are becoming much more important. They serve as small refuge islands in residential areas.

Combining lawn care and biodiversity

A short, walkable area and several taller zones do not have to be mutually exclusive. On the contrary, the contrast creates an appealing design feature. Some practical approaches include:

• Mow paths and play areas every one to two weeks.
• Cut selected strips only once a month, or even just two to three times a year.
• Leave dandelions and other flowers standing in chosen locations.
• Remove cuttings from taller areas so that more species can establish themselves.

This keeps the garden usable while parts of it develop into a lively meadow where insects and other small animals can settle.

Common mistakes during the first mow – and how to avoid them

A few deliberate steps in spring can prevent many problems later in the year. Typical pitfalls include:

• Cutting too short: This weakens the lawn and gives weeds and moss an easy advantage.
• Mowing wet grass: The blades clump together, the cut becomes uneven, and clumps form that suffocate the grass beneath them.
• Using blunt blades: Rather than being cleanly cut, grass blades are torn, and their tips turn grey-brown.
• Driving over soft ground: Wheel marks and compaction develop, water pools, and moss spreads.

Avoiding these issues can save you from costly remedial work later, involving a scarifier, overseeding and fertiliser.

Developing a better understanding of your lawn

Lawns are often seen as low-maintenance green carpets that simply need to be regularly “shaved down”. In reality, they are dense communities of many individual plants which, like every other garden plant, have needs: sufficient root length, light, air in the soil and time to recover.

Keeping this in mind makes it easier to understand why calendar dates are less informative than nature’s signals. Forsythia flowering, mild nights, firm soil and visibly growing grass together provide a highly accurate picture. Those who follow these signs can begin the lawn season more calmly and create the basis for a robust, dense and lively green space.