Winter Lawncare: How to Keep Your Grass in Top ConditionColin Campbell-Preston
Although Winter can be a quiet time in the garden, there are a number of steps you can take to protect your lawn through these cold, wet months. Our guide explains how to look after your lawn and keep it in the best possible shape between December and February. We also cover some common lawn problems that gardeners can experience during this time of year.
Keep off the grass
Your grass will damage easily during winter so if it’s wet or frosty, so try to keep off the lawn as much as possible.
The grass will continue to grow if the temperature is around 5 degrees Celsius or above, and may need mowing. However, don’t rush to mow unless you have to – at this time of year, it’s a good idea to keep your grass around 25% longer than you would in summer. If you do need to mow, wait until the ground is relatively dry – and if heavy frosts are expected, hold off until a warmer spell. Try to avoid letting the grass reach more than 50% over its summer height – at this point, any mowing will weaken the grass plants.
Aerating the lawn improves the drainage and allows more air to get to the root system. It’s important to aerate the lawn regularly throughout the year – once annually simply isn’t enough. You can buy various products to make the job less arduous – including lawn aerator sandals and lawn aerator rollers. However, during the winter months when the ground will often be wet, these could cause damage.
At this time of year, you’ll still need to aerate any areas of the lawn that look like they may be suffering from compactation with a garden fork. Signs of compactation include a spongy ‘thatch’ layer made up of old grass plants that have died, lawn disease, a lack of worms, rain run-off and rapid drying. If you don’t treat a compacted lawn, the problems can multiply – for example, a thatch layer acts as a barrier to air, water and nutrient penetration.
Drainage can be a huge problem during winter when you may find the lawn becomes squelchy to walk on, with puddles forming on the surface. You should avoid walking on the lawn where possible as this will cause more damage – however, you do need to treat these problems or the grass may turn yellow and eventually die.
Pricking or slitting the surface to 2-3cm (1 inch) can help, although deeper holes made to 10-15cm (4-6 inches) will provide better relief. Fill these holes with free-draining material such as horticultural sand – this will aid the water in flowing away from the surface to deeper and less compacted layers. You can use a garden fork or hand spiking tool to make the holes – or for a large lawn, you may want to purchase a hollow tiner. This has hollow spikes and removes plugs of soil as it passes over the lawn surface. Make sure all plugs of soil are removed from the lawn’s surface.
If you notice waterlogging, be sure to spike the lawn well in Autumn this year. If it is a significant problem and spiking is not working for you (for example, because you have heavy clay soil) you may wish to consider installing a drainage system so that the water runs away to a drain, ditch or soakaway. If there is no such place for the water to go, you could try replacing the lawn, laying new turf on a 5cm (2 inch) bed of sharp sand which has been overlaid with top soil, mixed with a good quantity of manure.
Keeping the edges of the lawn neat and tidy during the winter months is a much less arduous job as the grass doesn’t grow as fast! It also helps to limit the places that garden pests can hide.
After you’ve mowed the lawn during a drier spell, use long-handled edging shears to neatly trim the edges. Make sure you remove the cuttings – this is particularly important during winter as grass lying on the surface can make your lawn patchy, attracting pests and encouraging worm casts (see ‘Worm casts’ below).
If the edges of your lawn are particularly tatty, you can recut them using a half-moon edging tool. To cut a straight edge, use a plank of wood as a guide; or for a curve, use a length of rope or hose laid at the edge of the lawn. Where grass has grown over paths, use a sharp knife, cutting into the turf and pulling the pieces away. In future, if you find maintaining the edges of the lawn tiring, you could install spiked metal sheeting. This retains the edges of the lawn and stops the grass from growing into the borders.
Worms are generally beneficial to your lawn, improving both the nutrient content of the soil and the soil structure. However, they do have a habit of leaving ‘worm casts’ on the surface of the lawn which are little piles of soil that the worm has digested. This can create bumps in the lawn and although they get flattened during mowing, they look unattractive and can encourage weeds. Sweep away the dry worm casts with a stiff brush before you mow to avoid creating flat patches.
There are a couple of steps you can take to reduce the likelihood of worm casts on your lawn. Firstly, when you mow, make sure you remove the grass clippings straight away – and second, try to keep leaves and debris off the surface of the lawn. You will find there are a lot more debris in winter because of the weather, but this tiring task is well worth doing for the problems it prevents.
If you are really struggling with an excessive amount of worm casts, try applying a diluted mustard solution to the surface. This attracts the worms and you can hand pick them and remove them to another area. Alternatively, you could try Angus Downcast, a product which has been designed specifically to make the lawn unpalatable to worms. Ferrous Sulphate can also be an effective worm deterrent (see below under ‘Moss’). However, keep in mind that the benefits of having worms in the lawn far outweigh the detriment of a few worm casts – generally a lawn with worms will be far healthier than one without.
Snow mould is the term used for ‘fusarium’ or ‘fusarium’ patch when it occurs after a period of snow cover. This disease kills the grass plants, creating straw coloured patches on the lawn. These typically start out about the size of tennis balls and can spread with the right conditions. The perimeter of the patch may have slimy coating of white fungus, giving the patches an irregular shape. You’ll find that lawns which suffer from compactation, clay soil, poor drainage or shade are more likely to be susceptible. You should avoid late and substantial applications of nitrogen fertiliser, which can expose the lawn to this problem.
New lawns are particularly prone to mould after a period of snow – this is because they are still quite young and vulnerable, with little resistance to disease. However, all lawns – both young and established – can suffer, especially after prolonged snowfall. To minimise the likelihood of snow mould you should avoid scraping snow from the path or driveway onto the lawn; and if your children (or grownups) build a snow figure, clear it away once it is finished with rather than leaving it to melt slowly.
If you do get an attack of snow mould, wait until the Spring to treat it. Rake the patches clear of dead grass so that the soil is exposed, and densely spike the patches to a depth of around half an inch. Then add seed and fertiliser. Do not cover the patch with soil or you will create a bump in the lawn. You can use a light covering of polythene or straw if you want to keep birds away – removing this when the seeds have germinated. Keep the patches damp – and mow on a high setting initially for 2-3 months.
If your lawn has a moss problem, you can control the spread with iron (Ferrous Sulphate). You should wait until late January/early February when the weather is relatively mild.
Choose a Ferrous Sulphate product which is designed to kill moss without promoting any growth. This can be applied at 0.5 – 1g per sq/m in water (or follow the package instructions for your individual choice of product).
Note that if you apply Ferrous Sulphate towards the end of November this year, it will not only help to prevent moss spreading but it can also harden the turf, preventing disease and providing resistance to cold. As an added benefit, it will also help to reduce worm casts. For this purpose, you will need to apply a slightly stronger solution of 2g per sq/m in water (or follow the package instructions).
At Capital Gardens, we have everything you need to protect your lawn and keep it in top shape over the harsh winter months. Head to one of our three store locations to view our complete range of quality gardening products.