For the home owner, having worms in a lawn isn't a major issue as they provide food for birds, foxes and badgers.
However for the serious lawn enthusiast, professional green keeper and groundsman, worms in fine turf are more than an unsightly mess.
Anyone who's ever played golf, bowls, lawn tennis, croquet, football, rugby or hockey (just to name a few) know only too well that worm casts disrupt the playing surface. sticks to one's feet and generally males a mess.
Worm casts make playing ball sports a lottery and take the skill element out of a game.
If you've ever tried putting a golf ball across fine turf where worm casts are present you'll know exactly what I mean.
There's also the potential to damage mowing equipment.
Most professional users and domestic lawn enthusiasts will almost certainly use mowing equipment which is fitted with a roller.
A roller on a mower achieves two things. First it lightly rolls the surface of the turf ensuring any small bumps loose soil and grass is honed down and keeps the surface true so that balls roll properly and without deviation.
A roller also creates stripes. This is generally an aesthetic process. The light and dark stripes are created when a roller passes over the surface causing the grass leaf blades to lean in the direction that the roller is moving. When an operator returns on an adjacent strip the grass is forced to lean in the other direction.
A appearance of light stripe will always be when the grass leans away from you, the dark strip leans toward you. Basically the light and dark stripes are created when the grass reflects or captures light.
Worms casts stick to moving parts of grass machinery causing wear which quickly leads to grass cylinders, rotary and bottom blades to become dull. This in turn leads to bruising of the grass leaf blade rather than a clean cut.
If you notice the surface of your lawn become brown a day or two after cutting the likely cause is blunt blades.
When I started my greenkeeping career we used to apply dodgy chemicals such as chlordane and Lindane.
After an application of Chlordane, all worms in the top 3-10 centimetres of soil were killed. The chemical was efficiently residual meaning effective treatment lasted many years. Five years of control was not uncommon but regular use of a long period of time meant Chloraane residues are still present in some soils, even though Chlordane has not been used for over thirty years.
Chlordane is a known carcinogenic and was banned in the early 1980s.
I still have visions of our head greenkeeper mixing chlordane in a tank and using a Cushman Truck with sprayer attachment to treat our greens and tees. Very little personal protective equipment was used.
Carbendazim to be banned
Carbendazim has been used in the British sports turf and domestic professional turf care industries for years and became the de facto chemical for worm control after Chlordane and other chemicals became unavailable.
Carbendazim is a fungicide but when used on turf to control disease the side effect causes worms from being deterred from entering into treated soil. Carbendazim does not kill worms.
However there are wide concerns about Carbendazim's safety. Studies show that Carbendazim disrupts human and animal hormones.
Residues of Carbendazim in water which has run off of treated agriculture land are known to have infected trout and other fish stocks.
Carbedazim is banned in the United Sates and many believe it is a matter of time before its use in the UK is also banned.
"In Great Britain, the annual area treated in 2001 was 819,398 hectares, with arable crops accounting for 95% (718,757 hectares) of this use(13).
"For example, 38.6% of the winter oil seed rape grown (197,463 ha) in Great Britain is given at least one treatment of carbendazim, and 24% (71,548 ha) is given two treatments(14).
"Over the years, there has been a gradual reduction in carbendazim use – in 1996 just over two million hectares were treated with carbendazim in Great Britain, compared to nearly 1.8 million hectares in 1999 and 821,000 hectares in 2000(15). This is because modern conazole and strobilurin fungicides are more efficacious".
Chemicals used in today's domestic and professional turf care industry must have minimal residual effect. It's the grass professional's objective to deter rather than kill worms in the soil.
- CastClear is a non-pesticidal nutrient that increases turf health and suppresses worm activity thus eliminating work casts at the same time.
- CastClear contains more than 5% amino nitrogen with more than 15% bio-organic sulphur.
- CastClear is a combination of nutrient materials that have been clearly shown to reduce worm-cast levels on sports turf and lawns.
Scientific evaluation has shown that the product does not kill worms or reduce population, but does deter worms from travelling through treated soils.
It takes about seven days for CastClear to start working and deters worm activity for between ten and twenty days, depending on underlying soil and weather conditions.
CastClear has just been short-listed as one of the top products at this year's Glee Garden Retail Show