Mulching the soil helps to keep our gardens beautiful and fruitful. This warming duvet protects our precious soil against the ravages of Scotland’s ice and lashing rains.

Pull back a mulch and find soft workable soil. Without direct sunlight the ground will be around 2C cooler than open space but it’s a price worth paying. After all, the soil is ready for use when you want it and there’s not a weed in sight.

Unmulched ground is starkly different as I’ve quickly discovered when getting ready for sowing and planting. I confess I don’t always mulch where I dig leeks over the winter. So in April it’s a sair fecht driving a reluctant fork into concrete-like ground and trying to create friable soil out of the dry sods I’ve produced.

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And many soil organisms simply don’t function in very wet conditions: aerobic bacteria need a ready supply of oxygen for respiration. When this is driven out during flooding, these organisms are replaced by anaerobic bacteria which thrive without oxygen. As a result, the ground becomes sour and useless to our plants. Many of the soil’s nutrients are also leached away in the rains.

A protective mulch greatly reduces these problems.

So what’s the downside? Any garden is inevitably an artificial environment so there could never be a ‘natural balance’ between a gardener’s ‘friends’ and ‘foes’. The foes are often tough and highly opportunistic organisms. Tender young hostas, cabbage leaves and clematis shoots are magnets for slugs.

Unsurprisingly, these molluscs breed prolifically with such a bonanza of available food. There’s a population explosion and few potential predators can face eating repulsively slithery slugs. Most of my ducks will have a go at small Deroceras slugs but only a determined Muscovy can handle a large Arion. It’s prepared to single-mindedly traipse to and fro a ditch to wash down its mucus-coated prey.

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So if you’re troubled by slugs, choose mulch material carefully. A mulch must completely exclude light to prevent seeds from germinating, so you need a solid dark material or an approximately 12cm deep mulch of loose material. We never have enough compost or can afford sufficient spent mushroom compost or similar mulch.

Rather than using environmentally-damaging black plastic, it’s tempting to place a layer of cardboard on the soil and then cover with a thin layer of compost or other organic material. But damp cardboard provides shelter for slugs and makes a fine hors d’heuvre before tackling your newly planted broccoli.

You could always use cardboard over winter as a decoy. Lift before planting and you’ve a fine haul of victims to remove. I put this cardboard in the duck run and compost after a couple of days.

Alternatively or after this trapping, use something like dry slug-averse straw on a bed, or grit on an herbaceous border.

Plant of the week

Mahonia x media ‘Lionel Fortescue’ bears huge yellow, fragrant flower spikes, up to 40 cm in length, in winter. It is a large, upright shrub that can grow to 5 metres. It needs a semi-shaded position with soil that does not dry out in summer. Underplant with early early spring flowering bulbs for a stunning display.