Slug it out with pests

By Hannah Stephenson.

There's no doubt about it - slugs and snails are having a field day thanks to all the rain we've had, eating bedding plants, chomping on vegetables and munching their way through gardens nationwide.

The more vigilant among us have been doing morning and evening patrols, picking off the slippery suckers before they wreak havoc with our prized plants and suitably disposing of them.

As slugs and snails are particularly rampant in my area, I have resorted to putting young leafy plants, which these pests love, in pots and either placing the pots on metal stands which slugs have trouble in climbing, or putting copper strips around the pots to deter them.

The copper contains a minute electrical charge to deter the slug or snail. But even these have limited effectiveness and some still manage to reach the plants.

"Slugs and snails are likely to be breeding more successfully this year," says Andrew Salisbury, senior entomologist with the RHS.

"They will take advantage of any warm, wet weather to breed and often you find slug and snail eggs in damp and sheltered situations. The eggs are in groups a few millimetres across, spherical in shape and opaque white and you will need to dispose of them."

Don't throw slugs and snails over the neighbour's fence or into your garden refuse trug, he advises, because they will just escape and return to your plants.

The only way to get rid of them effectively (the squeamish perhaps shouldn't read on) is to do it with a pair of secateurs or plop them into a bag and bin them.

"I've seen figures that there are 15,000 slugs a year in an average garden," he adds. That's a lot of secateur work.

They will travel great distances for a tasty morsel. Salisbury has seen evidence of slug damage on really tall clematis and on magnolia flowers - they will go up and down a tree in a night, he says.

Even now, the most effective method of reducing these slimy pests is to use slug pellets, he says.

There are many types on the market, some of which are organic, but you'll need to re-apply them regularly in rainy weather, when they will break down quickly.

Alternatively, invest in a nematode biological control, a parasitic worm which works its way into the soil and will kill slugs underground, but may not be so effective on snails which tend to remain on the surface.

Nematode controls are available from mail order biological control suppliers and come as a powder which dilutes into water. The nematodes penetrate the slugs' body and release bacteria to kill the slugs, and should last around six weeks.

Beer traps and copper tapes around pots may help to some extent, but they won't eliminate the problem.

"You will never totally eliminate slug and snail damage in weather like this," he concludes, "but you can try to reduce the risk."

Encourage predators such as hedgehogs, frogs and toads into your garden by leaving a patch of wild area or installing a pond.

You can also encourage snail-eating birds such as thrushes into your garden by planting shrubs and trees which bear berries and create a nesting area.

Some slugs spend a lot of their time below soil level, feeding on bulbs, tubers including potatoes and roots. Snails are much less active in winter, but slugs will feed whatever the weather.

You could also plant sacrificial crops such as lettuce, which slugs love, to distract them from the crops you really value.

If you don't want an endless battle with these slimy creatures, the best solution is to plant species which they don't like, such as hardy cranesbill geraniums, hydrangea, pinks, hebes, potentilla, lavatera and plants with hairy or narrow leaves, or succulent types such as sedum.

Best of the bunch - Campanula The summer rain may have battered many plants but my dwarf campanula is still looking its best, bursting with purple flowers which show no visible signs of suffering despite heavy downpours.

In fact, campanulas come in all sizes, ranging from the delicate harebell to the giant chimney bellflower which tops 2.1m (7ft) and most of the taller ones will need staking.

Border campanulas make lovely cottage garden plants in shades of blue white or pink, combining well with other favourites such as white lilies, shrub roses and red peonies.

While some like C. lactiflora 'Prichard's Variety' flower continuously for more than two months, others may only last a few weeks.

They are tolerant of many soils and will thrive in full sun or partial shade. Good varieties include C. lactiflora 'Alba', which produces white flowers from July to September, and 'Loddon Anna', with its pale pink flowers appearing from July to October.

Smaller types which don't need staking include C. glomerata 'Dahurica', a gorgeous cluster-flowered specimen with deep purple flowers, while the dwarf C. lactiflora 'Pouffe' reaches just 30cm (12in) but has a mound-like habit and pale blue flowers.

Good enough to eat - Calabrese Also known as green broccoli, you can have fresh calabrese for much of the year if you plan your planting dates and different varieties carefully.

Like other members of the cabbage family, calabrese grows best in rich soil, so dig in some well-rotted manure or compost before planting.

Sow under glass in February and March, keeping the compost moist but avoiding wetting the leaves as the seedlings emerge.

The first sowings can be planted out in April or May, after about six to eight weeks. If you live in a cold area, they'll need to go under cloches or garden fleece.

If you want baby veg, plants should be spaced 15cm apart either way. For larger main heads, you'll need to give them a bit more space.

Try not to disturb the rootball when planting out and plant them deeply, so the first leaves are level with the soil surface. Sow further batches throughout April and May for a succession of crops.

Calabrese suffer from the cabbage family pests and diseases, so cover the crop with fleece when you plant them out and then with fine netting anchored to the ground to prevent cabbage white caterpillars doing their worst.

By July you should be cutting the main heads of earlier sowings, before the flower buds start to open. The head should be tight and completely green.

Three ways to... Design successfully 1. If you're creating a new border, don't be mean with it. Borders need space, at least 1.5m from front to back. Anything less means you won't be able to achieve any combinations or depth, so shrubs will spill over your lawn or obstruct a path.

2. Keep edges crisp. If you keep your lawn and path edges neat, it brings a whole feeling that the garden is well designed.

3. Consider how your corners are going to be used. Could they incorporate a seating area, a children's garden or just a shed? Themed corners enhance a well-designed garden.

What to do this week :: Reduce the length of wisteria tendrils by half.

:: Feed dahlias fortnightly and keep slugs and snails away from them.

:: Harvest fruit, veg and herbs while they are in prime condition. Freeze or store produce you can't use immediately.

:: Peg down runners on strawberry plants you want to propagate.

:: Buy winter varieties of spinach, which can be sown in August and September to crop between October and April.

:: Transplant wallflowers sown in May or June into rows 30cm (12in) apart, leaving 15cm (6in) between the plants.

:: Propagate African violets by inserting leaf cuttings.

:: Pinch off faded rose flowers. Cut a length of stem with hybrid teas, as this encourages more shoots to produce flower later.

:: Feed onions, leeks and celery on a regular basis.

:: Prune pyracantha, cutting back the side shoots to two or three leaves from their base. This will encourage a good display of berries next year.

:: Look out for bargains at garden centres as many will be offering deals on stock they didn't sell earlier in the summer.

:: Cut back wild geraniums, catmint and alchemilla when they start to look tatty, to encourage new foliage and a second flush of flowers