Controlling worms in a lawn

I wish I had been given a pound for every time I had been asked how to deal with worms in amenity turf.

Worm casts are the curse of every ground care professional and amateur alike - they are unsightly and messy and provide a superb seed bed for weed germination.

Of course, if you have a worm problem in the first place you should feel complimented because it means you have a fairly active soil with good aeration and humus content.

However, having said that it is no real consolation because your lawn in the meantime looks awful and your machinery will be suffering too.

So how do you rectify this problem?

• Avoid leaving leaves on the surface during the autumn and winter because this warm blanket of organic matter is an ideal restaurant for the worms.
• Do not allow a build up of thatch as again this decaying matter is digested by the worm which leads to casting deposits.
• keep the grass at a reasonable height.
• Avoid unnecessary watering as this leads to attracting more worms. In dry weather the worms will move deeper and by aerating regularly  and ensure good drainage you will discourage activity.

Of course, some of the above is counter productive to producing good turf and the finer the grass the greater the problem is likely to be. Inevitably you will need to turn to chemicals and in today's world that is a problem.

The law does not permit long life residual chemical build up in the soil. Gone are the days where a good dose of Chlordane would wipe out the worms. In fact Chlordane probably wiped out a few groundsman too before legislation got tougher.

One of the products we used which proved to be effective was Carbenzamin. This chemical was primarily produced to deal with fungal diseases such as Fusarium and Dollar Spot but as a side effect found to be a good repellent of worms.

Carbendzamin was found in tests to interrupt the feeding of worms near the surface by making the organic matter in which they feed unpalatable. Deeper feeding, non casting worms were found not to be troubled and continued to benefit the soil structure as normal.

Applying the chemical, which has a non hazardous classification, is most beneficial in Spring and Autumn and must be carried out when the soil is already wet as the chemical needs help in dispersing through the structure. It is advisable to carry out the treatment when rain is forecast within 24-48 hours but not imminently as run off may effect results as the chemical may end up next door rather than around the roots of your grass.

Heavy infestations may need a second application after 3-4 months and as a general rule we would always apply at the fungicide rate which is double the rate needed to treat worms.

For further information you can refer to the product data sheet here or contact Rigby Taylor direct who will be able to advise on suitable application and safety and technical data.

For treatment in the UK this spring it is advisable to contact reputable lawn care companies like The Lawn Company who are licensed to advise and administer products.