The soil are 'worm casts' see below:
Worms are beneficial in the garden as their burrowing activities improve the aeration and drainage of the soil and improve the nutrient content by digesting leaves and other organic matter and passing this into the soil. However in spring and autumn when the soil is warm and moist worm activity can ruin the appearance of a lawn by depositing muddy worm casts across the lawns surface.
To limit the damage caused by worm casts avoid smearing them into the lawns surface by avoiding mowing or walking on the lawn when wet. Wait for the casts to dry out and then brush them away using a stiff brush.
Another option is to deter worms by reducing the amount of food available for them. Remove grass clippings and leaf litter and scarify regularly (NB New turf should not be scarified in the first 12 months.). Earthworms also appear to dislike soils which have a high sand content, probably due to the lower moisture content and abrasiveness of the sand particle. Applying top dressing with a high sand content is one option. Earthworms also appear to dislike soil with a low pH and so the use of acidifying materials in fertilisers and iron sulphate can reduce worm casts.
As for the lawn supply and apply grass feed.
After a summer of hard wear and periods of dry weather your precious lawn deserves a helping hand so that it can recover this autumn. Here are a few tips on how to prepare your lawn for the winter and make sure it is thick and healthy for a really green start next spring.
Keep the surface clear
If fallen leaves are a problem in your garden try to remove them from the lawn as regularly as possible. If you wait until all the leaves have dropped, your grass will be fighting for survival under a cold damp blanket of moist, rotting vegetation. Try to do the job at least weekly throughout autumn to avoid any problems of disease. A rake, besom broom or mechanical collector will help you collect the leaves for your compost heap. Alternatively choose a lawn mower, which will do the job quickly and easily.
Rake the surface
If you have left the grass box off the mower during the summer or you have a hover machine which doesn’t collect the grass cuttings, then a layer of thatch will have formed on the soil surface. Not only does this layer prevent rain water getting through but it prevents grass plants from spreading and encourages diseases.
There are plenty of tools which can be used to remove this thatch – a spring-tine rake, ordinary garden rake or a mechanical raker. A couple of weeks before you carry out this scarifying, check for moss invasion and treat this with a product that contains a mosskiller such as Autumn. If you don’t treat the moss with a suitable mosskiller before raking it out, you may inadvertently spread the spores around the lawn and make the problem worse.
Help the water penetrate
Compaction is one of the biggest problems with lawns. But aeration in autumn will quickly help to strengthen the grass by improving drainage. Drive a fork or other spiked instrument into the top few inches of soil will allow rain and air to penetrate more deeply and at the same time relieve any compaction.
Without help, vital rainwater may run off a dry lawn and be wasted. A hollow-tine fork is ideal for the job because it takes out several plugs of earth to a depth of about four inches. These wide air channels not only relieve the packed-down effect created by pathway walking or children’s feet playing, but also aerates the soil. September is the best time to practice this deep spiking, followed in the spring with shallow pricking with a slitter aerator or solid-tine aerator.
Hope that helps
Andy
