lawn pests & diseases

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• Mowing a lawn
• Lawn care
• Lawn mowers
• Improving you lawn
• Sowing a lawn

Most lawns suffer from few pests and diseases and these can often be tolerated on general-purpose lawns. Fine-leaved grasses can be prone to a few common diseases if they are not growing strongly ­ but early treatment can prevent long-term damage.

Other lawn problems may be caused by the nature of the site or by algae, moss or lichen. Always consider treating the cause of such problems, such as drainage, removing fallen leaves, fertilising correctly before using chemicals. Although lawn pests are not easy to control with chemicals there are useful sprays that can be used against the most common lawn diseases.

Unless the problem has been experienced in previous years it should not be necessary to apply preventative sprays. Remember not to mow immediately before or after spraying chemicals on to the lawn, and heed manufacturers' instructions about restricting pet's access after spraying.

• Cats and dogs
  Urine often burns lawns; more so in dry weather. Pour water over the soiled areas. Use repellents. Re-turf patches that have been badly affected.

• Worms
  Worms may bring casts to the lawn surface, especially in the autumn. Simply brush away the casts.

• Leatherjackets
  These larvae of crane flies feed on grass roots, causing brown patches in spring and summer. An effective method of control is to cover the lawn with a plastic sheet at night to draw them to the surface. Remove the plastic early in the morning for birds to eat them.

• Chafer bugs
  These creamy-white, brown-headed grubs eat grass roots during the summer but they are usually far fewer in number than leatherjackets and rarely require action.

• Ant hills
  These are usually a problem only on dry, sandy soils. There are chemical treatments to apply to the centres of the hill, which can be opened up using a spade.

• Toadstools
  Toadstools feed on organic matter in the soil. They should be brushed off as they appear to prevent spore production. Rings of them are difficult to control with chemicals.

• Lichen
  These flat leaf like growths indicate impoverished soil, although shade may cause their presence. Improving the growth of the grass or applying lawn sand will help.

• Slime Mould
  These strange-looking fungi are a sign that the lawn is badly drained. The surface of the lawn should be aerated or the whole site drained to prevent the mould spreading.

• Algae
  This green or black slime is a sign that the lawn is poorly drained. Lawn sand usually kills algae quickly but it will reappear on consistently wet lawns.

• Snow Mould (Fusarium)
  Often in small areas but can spread. It occurs in autumn and under compacted snow. Scarify; avoid high-nitrogen feeds in the autumn.

• Red thread (Corticum)
  A problem only on starved, fine-leaved lawns in late summer, when leaves look bleached and covered with red threads. Strong turf however usually recovers.

• Dollar spot
  This fungal disease causes straw-coloured patches up to 5cm across. It is most common on fine turf and can be prevented by removing thatch through scarification.

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