How To Control Worms On Sports Pitches

Welcome to this new blog on How To Control Worms On Sports Pitches. In this blog l identify the issue, analyse it and then come up with the available options in terms of worm control/management that l have found.

In the UK we have 27 species of earthworms, only 3 of these are known to cast and the most common for casting is the lob worm. Worms thrive coming into periods of more mild and damp conditions, i.e. autumn and spring and are a major headache to groundsman and greenkeepers alike.

The Problem

Worm casts create the ideal seed bed for weeds, moss and undesirable grasses. Worms left unmanaged can create major issues to surface levels.

According to my research worms are less apparent in heavy, or free draining soils and don’t do well in course abrasive sandy rootzones. They thrive in rich, light medium loams.

Benefits of Worms Activity

Earthworms break down organic material in the profile and reduce thatch on the surface, so vital within soil life.

Stimulate microbe activity within the soil.

Boost aeration.

Negatives of Worm Activity

Dilute down sand/loam topdressing and contaminate with undesirable soils such as clay etc.

Where worms are active the surface is less free draining.

Worms encourage feeding animals, such as foxes, badgers and digging birds.

Casts get in mower blades and on rollers etc, making for varied mowing heights and poor cutting blades.

Casts create ideal seed beds for weed seeds etc.

Casts create bare area, often worse than play alone.

Over time can have major effects on surface levels.

How To Control Worms On Sports Pitches ?

Winter Sports

Ensure Winter sports pitches are top-dressed with a suitable course sports specific sports sand, this will irritate the worms.

The regular use of acidifiers, such as chelated iron, sulphur (take advise from your sales rep before considering, as this may lowering your soil ph level).

The use of Saponin, plant extracts-soap like detergents properties irritate the worm’s skin and often kills them. (but is off label use and cant recommend).

Box off clippings and keep organic matter and thatch to a minimum by regular verticutting/brushing and thorough end of season renovations.

Don’t over feed, this will encourage top growth and in turn more organic material possibly use of a growth regulator.

Keep the surface clear of leaves dropped from tree’s, which is a food source for earthworms.

Keep the surface free draining, so any winter aeration work will assist in this.

Wait till the surface is drier and try to disperse the casts with the use of a harrow/rake/dragmat or brush (with the build-up of regular sand dressing- effects of worms will become less of an issue).

Timing of Worm actively and treatment- spring and autumn or periods of damp, mild weather.

Cricket

The regular use of acidifiers, such as chelated iron, sulphur (take advise from your sales rep before considering, as this may lowering your soil pH level).

The use of Saponin, plant extracts-soap like detergents properties irritate the worm’s skin and often kills them. but is off label use.

Box off clippings and keep organic matter and thatch to a minimum by regular verticutting/brushing and thorough end of season renovations.

Don’t over feed, this will encourage top growth and in turn more organic material.

Keep the surface clear of leaves dropped from tree’s, which is a food source for worms.

Keep the surface free draining, so any winter aeration work will assist in this, the wetter the surface/profile the more worms will be active.

Wait till the surface is drier and try and disperse the casts with the use of a dragmat or brush.

Outfields- as above where possible but more than likely options are limited to just dispersing the castes using anything that works for you. Some groundsmen use dragmats/brushes/old plastic fencing/reinforced mesh/harrows, once the casts have dried later in the day.

Timing of actively and treatment- spring and autumn

Bowls and Greens

Ensure greens are top-dressed with a suitable course sports specific sports sand, this will irritate the worms.

The use of penetrants to help keep the surface/rootzone drier and less attractive to casting worms.

The regular use of acidifiers, such as chelated iron, sulphur (take advise from your sales rep before considering, as this may lower your soil pH level).

The use of Saponin, plant extracts-soap like detergents properties irritate the worm’s skin and often kills them. (But is off label).

Box off clippings and keep organic matter and thatch to a minimum by regular verticutting/brushing and thorough end of season renovations.

Don’t over feed, this will encourage top growth and in turn more organic material and possible use of a growth regulator.

Keep the surface clear of leaves dropped from tree’s, which is a food source for worms.

Keep the surface free draining, so any winter aeration work will assist in this.

Wait till the surface is drier and try to disperse the casts with the use of a dragmat or brush (With the build-up of regular sand dressings- effects of worms will become less of an issue)

Mustard Powder, is being used by some greenkeepers and the below text is taken from this worm suppression study- https://www.castclear.co.uk/files/WormSuppressingStudy.pdf

Mustard irritates the skins of the worms and causes discomfort and this makes them come to the surface, to then be dealt with as you see fit, but again cant recommend as off label, but is being used.

Mustard as a raising agent – An alternative method of getting earthworms out of the ground is to pour a mustard solution on the ground. To make the mustard solution, add 25 ml volume of mustard powder to 0.75 litres of tap water and shake well. Keep checking the area where you poured the solution (and surrounding area) for ten minutes to see if any earthworms emerge.

Initially this was applied to the whole area, but was then reduced to per square metre rate following initial failures and feedback from worm researchers.

When putting through a pressure or knapsack sprayer, it is important to pass the dissolved liquid through a very fine mesh sieve first, as it can have some trace impurities that could clog up your nozzles or other fine parts of your equipment.

Timing of actively and treatment- spring and autumn

How To Control Worms On Sports Pitches Conclusion

The use of saponins (e.g. purity soil conditions) is not backed up by science, with no avaible evidence to the possible harm we may be doing to the soil environment.

I can’t professionally recommend the use of saponins, but l am not going to pretend it’s not widely used and that l haven’t used them myself.

Cultural, most of us would love to work more culturally and at times this can be an effective option. But for those with heavy soils and wet winters this isn’t always an easy choice, which can force us into using something that works quickly (saponins). Saying that have we looked into acidifiers and other options listed above first?

Acidifiers are worth looking into as well, they need more regular applications and you also need a sprayer, so this may rule out some readers. Though even a knapsack sprayer would be a worthy investment (small areas), more of a challenge for grass roots clubs on winter pitches and limited resources.

Acidifiers may also lower the soil pH levels which will deter worms, but always take advice from a facts-based sales representative. You don’t want to lower your pH too much or you can create other issues such as nutrient lock up and encouraging the wrong type of grasses.

Sand Dominated Profiles

The good news is if you are topdressing a winter sports pitch or green with a coarse (angular) sports sand, managing (dispersing) the casts is either easier or will become easier as you build up the level of sand which irritates the worms.

Winter sports and greens that increase/maintain their use of sand and will also result in freer draining surface with better drainage, all this should hopefully lead to a drier and less worm effected surface.

Acidifiers and the use of iron in the form of sulphur are good options to HELP control worm actively, along with the added benefit of hardening the turf, which makes this worth exploring.

The main control period for casts is autumn and spring, so not a year-round challenge, maybe resources can be found to at least help you control casting until we hit the cold spell in December/Jan.

What works for you, what can you share with the community, please let us know in the reply box below.

I hope you found How To Control Worms On Sports Pitches a helpful blog.

Brian

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