Mark, in Marton, Middlesbrough, has been told by his father that he should apply a mulch to his flower borders. He wants to know what a mulch is and what it does, and if it is worth the effort.

MULCHING is one of those jobs that requires a bit of forethought and effort, but it pays dividends in saving time and trouble later on. It means covering an area of garden and surrounding plants with a substance which will exclude light and air and retain moisture.

A mulch can be made from many materials, both organic and inorganic.

Probably the most common traditionally are rotted stable manure or straw. Bark chippings, black polythene, spent mushroom compost, spent hops, seaweed, sheep wool, sawdust, wood shavings and gravel can also be used. Cardboard and old carpet are quite effective although not as aesthetically pleasing.

The soil naturally holds a reserve of water, from rain or snow or maybe from a nearby stream. This can gradually drain away or be lost through surface evaporation. Moisture is also lost through transpiration, the process by which plants draw up water from the soil through their roots and then keep themselves cool by passing it out through their leaves.

When the weather is hot, more water is lost and in order to keep the plants happy you need to keep watering. But if you use a mulch, the moisture is kept in to a much greater degree.

Mulching keeps down the weeds, deters cats from using soil as a toilet and to some degree holds back the march of the slugs. Over time, the matter gets incorporated into the structure of the soil and opens it up, assisting with drainage and nutrient uptake. Applying a mulch is a win-win activity. It doesn’t take much physical energy to undertake, and will reward you and your garden ten-fold.

Jobs this week

COMPLETE the pruning of fruit trees and continue planting in suitable conditions. It is your last chance to complete winter spraying with tar oil wash. Spray outdoor peaches, apricots, and nectarines with a fungicide to control peach leaf curl – as a preventation now rather than later as a cure.

Cut back autumn fruiting raspberries to about 15cm high and trim the tops of canes of summer fruiting raspberries. Prune figs.

Winter and spring bedding plants such as pansies and primulas need to be dead-headed to encourage a long flowering period.

Ventilate greenhouses in mild weather, but close up from late afternoon to store heat into the night. Clean the greenhouse prior to spring sowings.

It is a good month for a dressing of bonemeal to shrub borders and beds.

It takes a few weeks before it starts to break down in the soil, so it will be a ready source of plant food when the plants need it in a few weeks.

■ Brigid presents the BBC Tees Gardening show on Sundays from 1pm to 2pm. Questions can be answered on the day by emailing brigidpress@bbc.co.uk any time during the week, or texting 07786- 200995 and phoning 01642-225511 during the show. Written letters can be addressed to Lazy Dayz,10 Farm Road, Houghall, Durham, DH1 3SF.