Although we generally tend to the lawn reasonably well during the mowing season, it is largely abandoned from October to March. So far there has been little or no frost to call a halt, and growth from July on has been truly exceptional.
he ‘non-mowing’ season is almost as long as the mowing season, there’s only a month or so between them. However, most lawns take on an unkempt look during the late autumn and winter and this often persists until the grass is cut in spring, when it has to be cut hard and the grass takes weeks to recover.
Grass growth surged in September, making a second peak of growth after a fall-off in summer. Although this late flush of growth is nothing like as strong as the late spring/early summer surge, it is important for making a lawn look good again after the wear and tear of summer. Sods of grass can be lifted with a spade in areas that are not worn and moved to spots that have been damaged. Or the soil in the worn areas can be broken up with a fork and lawn seed sown.
Even after the autumn surge of growth is over, growth continues tailing off into November and even December. For the eight weeks from mid-December to about mid-February, there is very little growth. Soil temperatures below 6C halt grass growth, but there are short periods when the temperatures rise above this, and there are stop-start periods of grass growth that occur right through winter, especially in southern parts.
Autumn sees a shift in the balance between grass and lawn moss, which likes moist weather and manages to grow during the cooler part of the year when grass growth is slow. This is the key time to apply sulphate of iron to control lawn moss, either as a dry powder from a garden fertiliser spreader, or diluted and watered or sprayed on.
Dead moss can be removed with a power scarifier, which you can hire, but it’s not essential to do so. If the dead moss and old grass is ripped out, some lawn seed can be spread over the ground to restore the sward with new plants. Organic moss-killers of various kinds are available and don’t blacken the grass, or stain paving, as sulphate of iron can do.
Apply an autumn lawn fertiliser, a general high-potash fertiliser (such as 0-10-20), or one with a small amount of nitrogen. This will give the grass a late boost but also toughen it and leave it in good stead for the following year, as the phosphorus and potash is retained in the soil. Apply 20-30g per sqm of fertiliser.
Make sure fallen leaves are removed within a fortnight or so because they will kill the grass by starving it of sunshine. Mowing should be carried out late into the season, as long as the ground is not soggy, which will compact the soil.
In November, even December and January, and certainly early spring, grass should be mown as needed. Usually this means mowing once each month when the ground is firm – and these trims can make an enormous difference. If the moss is killed off and the grass is given some fertiliser, it will look green and healthy, and if it’s mown it will look neat. There will be next to no effort involved in getting the lawn into shape next spring and it won’t suffer from having to be chopped back then.
A lawn grown for wildflowers is treated differently. No fertiliser is used and moss is not usually as big a problem because broadleaved wildflowers compete better with moss – the broadleaves flatten down on top of moss and kill it. Because a wildflower lawn is not as vigorous in growth, it may not need mowing between October and March. But a winter mowing can be carried out if there is too much growth. Remove fallen leaves from a wildflower lawn too.
October onwards is a good time to introduce new wildflowers into a wildflower lawn. Plants of attractive species such as birds-foot trefoil, cat’s claw and self-heal can be raised in individual cell trays, sown in summer, and planted out in an informal fashion to establish during a period of little growth. Lift and turn a sod about 15cm square, and deep, planting the new plants individually into each lifted sod.
The existing plants will recover the space but by then the new plants will have rooted successfully. When introducing wildflower species to an existing lawn, make sure to match your choice of species to the conditions available. Birds-foot trefoil likes very well-drained soil, while self-heal likes moister soil.
Although you might be tired of looking after your grass, any effort now will give good results next year.
- ‘Persian Spire’ is a variety of the Persian ironwood tree but is strongly upright in shape. It has purple new growth in spring and produces an outstanding display in autumn in shades of purple, red and yellow. Now is a good time to plant and benefit immediately from its fine show, even when a young plant.
- If there’s one thing that has given us pleasure during lockdown, it’s listening to our garden birds. Learn what they like with Dan Rouse’s How to Attract Birds to Your Garden (DK, £16.99), out this week.
Just do it
- Start by tidying flower beds and borders, and leaving the cut stems and seedheads lie for a day or so before giving them a shake to shed their seeds. It’s all food for ground-feeding birds such as dunnocks, wrens and robins that switch to seeds when insects are scarce.