If worm casts are affecting your autumn lawn enjoyment, take heart. We have the perfect non-pesticidal deterrent to ensure grass stays cast-free in autumn and winter.
Why are worms casts an issue? Well, when it comes to mowing, it pays to know that they smear when you run over them with a mower – which can dull the blades on a cylinder mower. Also, once they’ve been flattened, they provide the perfect gap in the sward for weeds to colonise.
If you’re lucky enough to get a dry enough spell when there is no dew on the grass, you can sweep them into the lawn to disperse them - and they don’t cause an issue. The problem comes when it’s too damp to do this. Read on to learn about the creators of these little muddy lumps and a highly effective solution.
Cast-Making Culprits
The most likely cast-making culprits are from a class of worms called anecic worms (specifically Lumbricus terrestris – known as the nightcrawler, common earthworm, or common lob, and Aporrectodea longa – known as the black-headed worm).
Nightcrawlers or common earthworms are deep-burrowing worms and are very common in UK gardens. They can grow to around 25cms long, burrow down to a metre or more in depth, and live for up to ten years!
Common Earthworm Lumbricus terrestris
Black-headed worm Aporrectodea longa
Aporrectodea longa on the other hand can burrow down to an impressive 3m deep – a fantastic strategy to help them survive hard winters and freezing soil.
Earthworms emerge at night, grab dead leaves and other plant material and pull them down into their burrow to consume. The small mud pile it leaves behind is very fine soil that has passed through its gut.
Whilst the casts left behind by active worm populations are unsightly, the worms themselves are aerating your soil beneath the surface of your lawn and creating channels for water infiltration. This in turn can help roots to penetrate deeper into the soil – producing stronger plants.
For this reason, keeping worms active below the surface is not necessarily a bad thing. Aiming to deter them rather than kill them is therefore the ideal approach.
Using Nutriflo Casting
Nutriflo Casting is not a worm killer, it is a worm deterrent. It works by creating a temporary chemical environment at the soil surface that casting worms do not like. This causes the worms to remain lower in the soil profile.
This product is a soil amendment, not a pesticide, and so results are not seen instantly. Apply between September and March and then reapply fortnightly until the worms have been deterred and you no longer see casts. Nutriflo can be applied via knapsack or boom sprayer.
Deterring and Fertilising
Nutriflo Casting will do more for your lawn than deter worms. It contains nitrogen, sulphur, iron and other trace elements to help feed your grass, and improve its health and colour – important processes as grass transitions to cooler temperatures.
However, the nutrient ratios in Nutriflo are deliberately modest as its main function is to amend the soil rather than act as an autumn lawn fertiliser. For this reason, it should not be used in place of a normal autumn fertiliser regime.
To treat your lawn in autumn, use a fertiliser like Nutrigrow 3-12-12 first, and then apply Casting around one week later assuming the weather conditions are appropriate.
With the right innovative products and considered approach to lawn care, you can achieve a healthy cast-free lawn and maintain a healthy population of active earthworms!
Speak to our technical team if you have any questions about worm casts or worm deterring soil amendments.
This post was written in collaboration with Harry Glenn
Harry Glenn
Harry Glenn is Agrigem’s Technical Account Manager in charge of sports turf.
Prior to his move to Agrigem, Harry enjoyed a career in business development with, among others, a well-known sports turf contractor. This role exposed him to some of the UK’s most prestigious sporting venues including Cheltenham Racecourse, Wimbledon, Wentworth and Lords - delivering a lifelong appreciation of the benefits of high-quality sports turf.
An experienced Account Manager, Harry has a genuine interest in the sports turf sector and underpins much of his advice and guidance with practical experience at the coalface of turf growing. When not talking about turf, Harry is playing on it, competing at county level golf with a scratch handicap!
Article Notes:
1. NutriFlo is a trademark of Agrigem Ltd. It contains 5.10% w/w total nitrogen, 5.10 % w/w ammoniacal N, 5.77% w/w sulphur (S), 14.40% w/w sulphur trioxide (SO3), 0.03% w/w calcium (Ca), 0.000% w/w copper (Cu), 0.280% w/w iron (Fe)
2. Use plant protection products safely. Always read the label and product information before use. For label and safety information, refer to the manufacturer’s website.
3. Only certified users may apply professional plant protection products. Find out more about safe use of pesticides here.
