Looking After Your Lawn In Winter

Try to rest the lawn as much as possible during winter. If practical keep off when wet or frosty, as the grass plants are not actively growing; if damaged, they will not repair themselves until the spring.

Mowing: Put simply, mow the lawn as and when it needs it ! Changing climate conditions now mean that lawns can carry on growing well into the winter, and giving the lawn a light mow every now and then is certainly a good idea. The frequency of mowing will depend upon weather conditions and temperatures at the time; do not mow if heavy frosts are expected, or if the ground is very wet. Click here for more information about mowing.

Pests: Be vigilant for any signs of Leatherjacket or Chafer Grub infestation - as you are spending less time in the garden during the winter, damage can easily be overlooked. Fact sheets on Leatherjackets and Chafer grubs are available on request.

Aeration: Providing it is not done when it is frosted, aeration during the winter months will benefit the lawn. Aeration will relieve compaction, improve drainage, and allow more air into the root system, leading to a healthier, more vigorous lawn. Experienced gardeners sometimes talk about the beneficial effects of ‘getting some winter’ into the lawn. What this means is that when frost penetrates the soil via the holes caused by aeration, pockets of moisture in the soil freeze and expand, and this helps to break up the soil, thus maximising the benefits of aeration. In tests, grass roots have been shown to proliferate around the holes created, due to the ‘pruning’ effect of the tines cutting through the roots. Click here for more information about aeration.

Clearing leaves and debris: This is important. Use a light rake or brush to keep the lawn free of leaves and debris. If left, they can turn the grass yellow and even kill it off by blocking the light. This can also contribute to moss development and weed ingress in areas where the grass has died back. Furthermore, the slimy, wet morass of decaying leaves can contribute to lawn disease. Specialist leaf sweepers and lawn vacuums are available for hire from local garden centres or DIY stores for larger lawns.

Worm Casts: Worms are beneficial to the soil structure of a lawn and also improve the nutrient content, but their casts can be unsightly, and if rolled into ‘pancakes’, can kill the lawn below. Of the 27 species of worm that are native to Britain, only 3 species produce casts. Worm casts are best left to dry and then swept or brushed away with a stiff brush. However, if required, we have a treatment which will control worm casts. Click here for more information.

Service your mower: Service or, if necessary, replace your mower now, ready for the next growing season, and whilst the dealers are less busy. Always make sure that the blades are in good condition and are sharp.

Snow Mould: This can be a problem. If you are concerned, please click here for further details.

Scarification

Why scarify?

Scarification is a very important operation. Effective scarification will improve the quality of the lawn, by removing waste organic matter, and will also improve the effectiveness of other operations that follow at other times of the year.

What does scarification do?

Scarification is carried out to remove organic matter from around the base of the grass plants and tidy up any straggly lateral growth. In a nutshell, scarification removes material, usually in the form of thatch or moss, that will otherwise prevent good dense grass growth. If lawns are not scarified, debris will build up and lead to other problems, including poor drainage and difficulty in getting water and nutrient down to the rootzone, where they are of most benefit. Furthermore, thatchy and/or mossy lawns will feel excessively spongy underfoot, and will not be very hardwearing or drought tolerant.

Scarification creates space around the roots of the grass plant. Once this has been achieved, the grass will be encouraged to spread and fill the space, thus creating a denser sward.

 
 
Thatch – a layer of dead or dying grass and other organic matter at the foot of the grass plant but above the soil. if this layer is excessive, the lawn will start to suffer. Scarification reduces this layer to an acceptable level. Click here for more information about thatch.
 

When should scarification take place?

Late summer or autumn is generally regarded as being the safest times to scarify, when temperatures are lower and there is sufficient moisture to encourage good recovery from the effects. It is important that the grass is growing fairly well and that any space created is filled by desirable lawn grasses. If growth is slow, there is a higher risk that the gaps will be filled with unwanted weeds or weed-grasses. It is also desirable to promote grass growth after scarification. This means that over seeding should be considered where large amounts of thatch and/or moss have been removed.

 

 Please remember:

Scarification can create large amounts of waste. We will either put this waste on your compost heap, or leave it bagged for your disposal. Alternatively, for a small charge we may be able to dispose of it for you. Scarification can be quite brutal in its operation, particularly if the thatch levels are high, when the lawn may require several weeks to recover. It may be necessary to re-seed bare patches where large amounts of thatch and/or moss have been removed.

The benefits of Scarification:

  • Degrades thatch and increases nutrient uptake into the grass plant
  • Improves surface drainage
  • Released nutrients encourage root development, not disease
  • Increases turf vigour and wear resistance
  • Promotes improved root development and sward density
  • Maximises the benefits of aeration

Dependent on the levels of moss and/or thatch present, it is often more effective if two or more scarifying ‘passes’ are used. However, it is important that the passes made are not at right angles to each other, as this is too brutal and could result in excessive damage to the lawn. It is far better, and more effective, if the second pass is at approximately 40-45º to the first.

Thatch

Thatch is a layer of organic material which can be found above the soil’s surface, but below the grass plant leaves. Thatch is defined as a tightly intermingled layer of dead, dying or living plant material, such as stolons, rhizones, stems, crowns, nodes and leaves – in other words, all parts of the turf grass plant.

In small, controllable amounts, thatch is very beneficial to the lawn, by preventing moisture loss through evaporation, and protecting the important meristematic regions (areas of growth, such as the crown, which can be found at the base of the grass plant). Thatch also provides a ‘cushioning’ effect for playing or walking on. However, poor turf management can quickly result in high levels of thatch and many related problems.

To determine the level of thatch present, a section of turf is removed. Looking directly below the green leaves, the amount of dark brown stem and root tissue is measured (see photograph below; the thatch layer is shown between the dotted lines). Thatch becomes a problem when it is any thicker than ½” or so.

An excessive layer of thatch will bring problems to a turf grass sward:

  • The lawn will feel spongy underfoot
  • Water filtration is reduced
  • It will provide an ideal food source and living conditions for many turf grass fungal diseases and insects
  • It increases the incidence of mower scalping the lawn
  • It will promote the growth and invasion of weeds, moss and weed grasses such as Annual Meadow-grass (Poa Annua).

The two main types of thatch found in domestic lawns are : The fibrous type (tough, dry, very wiry in feel, usually brownish in colour), which is typically found in acid situations, and the more common spongy type (yellow / brown in colour, usually soft and often waterlogged, and sometimes has black streaks running through it. This type often smells of eggs or stagnation (hydrogen sulphide), and will sometimes be found in heavily watered areas, or on heavy clay soils.

The benefits of controlling thatch through maintenance procedures such as scarifying, brushing and raking, and top dressing, frequently include : keeping a firm, dry turf surface, increasing the depth of the grass rooting system, and improved distribution and penetration of irrigation and rain water.

In addition, scarification will create space around the base of the grass plants, and new growth will be encouraged to fill the space, resulting in a denser, thicker sward of grass.

Usually the main option for addressing a serious spongy thatch problem has been scarification. Whilst there is a place for this operation, scarifying is a brutal operation which often has a severe effect on the lawn’s appearance, and can result in extensive overseeding being required. Where excessive thatch is the problem, there is now an alternative approach - Thatch Eater - which should be considered.

Thatch Eater is a combination of beneficial soil bacteria and fungi, specially selected for their ability to rapidly degrade thatch and other organic matter and to release locked-up nutrients for plant growth.

Applied after aeration, Thatch Eater will release a lot of the nutruent from the recycled thatch and promote healthy growth.

  • Degrades thatch and increases nutrient uptake into the grass plant
  • Improves surface drainage
  • Released nutrients encourage root development, not disease
  • Increases turf vigour and wear resistance
  • Promotes improved root development and sward density
  • Maximises the benefits of http://fourseasonslawncare.info/index.php/help-advice/9-aeration>aeration