[mrfizz]

I have terrible problems with worm casts on my lawn (some bigger than golf balls) during Autumn and Winter especially. I have been told that increasing the acidity of the soil under the lawn will deter the worms and force them to go and live elsewhere. Is there any reliable way of doing this without risking killing off patches of grass or risking the health of the grass in general? I like my lawn and i'm fed up now of the lumps and bumps that the casts create and having to fix them every Spring!

[Bazmundo]

Seems croquet is good for something, some advice here: http://www.oxfordcro...worms/index.asp

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Worms do not seek soils with high acidity (low pH = acid). There are products that intentionally acidify the surface of the soil which claim to drive the worm down from the surface. The acidifying agent needs reapplying at 2-4 week periods. I would raise an eyebrow at this approach. Grass, like worms, has a preferred pH range and the viability of the grass is likely to be affected if its conditions are modified. There are grasses however which like acidic conditions, but they may not offer the required turf properties, e.g. hard wearing, drought resistance, etc. Also, if you pour something on the top of soil and are reapplying it frequently, where does it go to? Down seems the obvious answer so the worms get driven further and further down?

The Croquet Association advises in its publication 'Croquet Lawns: Their establishment, improvement and maintenance', section 58:

"As the pH drops towards 5.5 the spraying will become less necessary. The cheapest way to lower the pH is to apply Calcined Sulphate of Iron at ¼oz (7gm) per sq. yd."

Example products: 'Worm Clear Plus' (spray) and 'Sulphur Worm' (granules) from http://www.greenacres.eu.com/ also http://www.greengard....co.uk/lawn.htm (Oct 2005). The product 'CastClear' (2010) claims to deter worms - its principal component is ammonium thiosulphate, hence liberating sulphur and acidifying the soil.

[Nigel Bolton]

Don't discourage worms by declaring chemical warfare, they are actually doing the lawn good by providing aeration and carrying organic matter deep into the soil. Over acidification of a lawn will encourage moss, which, if you value your lawn, is an absolute bugger to get rid of, once established.

Sweep the casts gently with a broom to break them up, and try not to stand on them, as worm cast pancakes make excellent seed bed for weeds.

To remove some worms, stick fork into lawn and wiggle. Worms will think they are being chased by a mole, and will surface, and will come up nice and clean. Place these worms in the compost heap, or if you know someone who likes fishing, let them have some. Holes left by the fork tines will improve aeration still further.

N.