Lawn moss treatment

Moss treatment

A serious problem in spring and autumn that is most often found where drainage is poor and the lawn is in the shade. Moss is the name for a group of primitive non-flowering plants that quickly spread as a spongy mass on undisturbed soil.
They reproduce from millions of microscopic spores produced on the leaves that float away from the mother plant on rainwater.
When found in a lawn, moss is a good indicator that:
Ground remains wet for long periods
Nutrient level of the soil is low
Soil is compacted and lacks organic matter
Grass may be cut too short or even scalped down to bare earth
Area is shaded from regular sunshine
Burning off moss with a suitable lawn treatment is easy, but unless some of the conditions that favour the plant are changed, then the moss will return, springing up from spores that remain on the soil surface.
Apply a lawn treatment containing a mosskiller and then try to remove the causes. Spiking will improve drainage and over-seeding with a grass seed mixture especially for shaded areas will improve the vigour of the lawn.

How to treat moss.
Don’t try to rake out the moss before it has been killed by a lawn treatment because this will only spread the spores around and make matters worse. Then rake out the debris. Now comes the hard bit. To prevent the moss from returning you need to take action to improve the conditions for the grass and make it inhospitable for the moss.

Mowing
Check the cutting height of your mower. Never scalp a lawn too short. This will weaken the grass and leave the soil open to moss invasion. Where moss is a problem leave the grass so that it is at least 2.5cm (1”) long at all times. Mow regularly, at least once a week, to encourage the spread of grass plants. In autumn and winter leave the grass even longer. See recommended cutting heights in our lawn cutting section.
Drainage
Improve drainage so the soil doesn’t remain permanently wet. This means spiking the affected area to let in air, improve drainage and generally reduce the compaction of the soil. There are two methods. For slight moss problems drive a garden fork into the area at 15cm (6”) intervals as deep as possible. Where returning moss is a continual problem use a hollow tine tool that can be driven into the lawn to remove plugs of soil at regular intervals. These plugs need to be brushed off the lawn and the holes filled with good soil. This enriched dressing will improve the organic content of the soil, improve drainage and reduce compaction. As a result, roots of grass plants will be encouraged to root even deeper and the grass should become thicker and healthier.
Avoid watering the lawn in summer unless the grasses are wilting from lack of moisture. If watering is essential, spike the area with a garden fork to reduce run-off and to ensure good drainage of any excess water. In areas that get water-logged regularly you will need to build a soak-away system to take away any excess water. This could be a simple soak-away sunk at the lowest point of the lawn. Dig a hole 60cm (2ft) square and 1 metre (1yd) deep. Fill the bottom 60cm with broken bricks and other rubble – top this with a 15cm layer of small stones topped off with a layer of free-draining top soil. If the lawn still remains wet, then you may need to dig out gravel tunnels 30 cm down which will naturally take water from the lawn to the soak-away.

Remove shade
Wherever possible cut back branches of trees and reduce the height of hedges to allow the sun to reach all areas of the lawn. Sun and wind will dry out the soil surface and moss will therefore be discouraged. If shade can’t be reduced, bite the bullet and turn this area of lawn into a bed and plant up with shade loving plants.

Feeding
Starved grass can’t dominate the playing field of your lawn unless it receives some supplementary energy. Feeding the lawn in spring, again in the summer and finally with an autumn dressing will help no end. It helps grass to strengthen over-winter and control any existing moss that would otherwise spread throughout the dark days of winter. A well-fed lawn is thick, strong and vigorous because it encourages the growth of grasses and inhibits the growth of moss.

Aerating
In autumn take out plugs of soil with a hollow tine tool and brush Enriched Lawn Soil into the holes that have been created and leave a thin layer of the material on the soil surface so this can be pulled into the ground by worms. This is especially beneficial on light sandy soils that are shallow.

Reseeding
Where bare patches have occurred as the moss dies off, re-seed the area with a shade tolerant grass seed mix.
Rake the soil to make a fine seed bed and sprinkle the selected grass seed over the area lightly. Cover the seed with good soil and keep moist until the grass seed germinates. If the whole lawn is thin, then over-seed the complete lawn with a sprinkling of this grass seed applied in the autumn or spring. In just a few weeks you will have a thick, dark green lawn that will be strong enough to fight off moss problems.