Even the winter pansies are not yet safe from the slugs

Dec 29 2007 by Val Javin, Huddersfield Daily Examiner

SOME weeks ago, I wrote an article on the life of worms in our gardens and how they do such good work for us.

Unfortunately, Mr Maloney from Kirkburton doesn’t quite see it that way. He wants an effective and lasting treatment for the casting worms in his lawn. Up until a few years ago we had a collection of chemicals, available to amateurs gardeners, that could be used to kill off these worms in our lawns but these have now been banned because of the dreadful damage they have been proven to do to the environment.

Mr Maloney’s attempts with Derris Dust have not worked because the chemical is not designed to kill worms, only what it says on the box. The Allobophora worms that cause the casts on the surface of the lawn eat partially decomposed organic matter and then exude their casts onto the surface of the lawn and so, one way of reducing the incidence is to clear the lawn of all autumn debris before the worms have a chance to pull it into the soil and to scarify the lawn at least twice a year to remove the thatch.

These worms are less prevalent in acidic soils and so by using high nitrogen fertilisers in spring you can lower the soil pH gradually to help reduce the populations. This may of course encourage more moss in your lawn but that is a price you may have to pay!!

Mrs Shaw from Meltham has planted up some delightful winter pansies in her garden, only to be faced with something eating the flowers and leaves.

Without actually seeing the damage it is difficult to put an exact diagnosis on the problem but I suspect that your pansies may have been attacked by a few last minute slugs or snails before they hibernated or there may have been a flush of the violet aphid that attacks pansies.

The adult aphids are green and yellow and can develop into large colonies on the underside of the leaves, causing puckering and distortion.

One of the non-chemical, fatty acid, organic sprays will kill off the aphids quickly without harming anything else, although the recent cold weather will probably have put paid to the antics of the aphids, slugs and snails, certainly until springtime.

Clean off any damaged flowers and foliage, firm the plants back into the compost and then give the surface of the compost or soil a light cultivation to help activate some new growth when the weather get a little better. You can also add a light dressing of a general fertiliser in early March to give the plants a boost.

Brian Morriaty from Meltham has written to me again for help in identifying nuisance and invasive herbaceous perennials.

This is a vast subject that will require a lot of column inches (or should that be centimetres these days) to resolve and I will address the issue more fully in spring when it is a good time to consider lifting and dividing many of our summer and autumn flowering herbaceous plants. However, invasiveness or otherwise comes from the plants natural habit of growth, and this should always be checked out before you buy from a nursery or garden centre or receive a small piece from a neighbour or friend. Some years ago I was given a small piece of a double flowered Saponaria officinalis (Soapwort) and it has run amuck across one area of my garden ever since.

This is because it grows from deep, underground rhizomes ( underground stems) and, in my sandy soil, it can run as freely as it wishes.

So, the secret to resolving the problem is to study the plants underground growth, be it roots or rhizomes, before you even consider what the top growth might do. If in doubt, keep the plant isolated in an old bucket to stop it from spreading and until you are sure that you can keep control over it.

As we start another new year, I feel sure that the established gardening problems will continue and there may be one or two new ones to challenge me and I look forward to receiving your letters about them.

Remember that photographs can help in identifying and therefore resolving problems.

So, if you have any questions or queries that you want help with or gardening related subjects that you would like to discuss, why not write to me at Gardening Questions, Features Office, Huddersfield Daily Examiner, PO Box A26, Queen Street South, Huddersfield, HD1 2TD.