Compost, bark and pea straw or similar materials are great winter mulches. If you have a large garden, hire or buy a shredder and make a mulch of prunings and hedge clippings. Light materials should be composted as they will blow away and the precious layers are quickly lost .
All those lovely leaves you were dreading dealing with are natural mulch under deciduous trees and will protect the roots, so leave them lie. If they fall on the lawn, however, you must rake them up and remove them or they will kill the grass
Wet sand or ash can become as cold and frozen as the ground you are trying to insulate.
Gravel gardens are great for dry climates. Think of a riverbank or the beach on a hot day - hot on the surface but cool and moist just a few centimetres below the surface. Avoid very pale stones that reflect and thus increase heat in the area of the plant, or very dark stones that absorb it.
When to Mulch The best time to mulch for water conservation and weed suppression is in the spring after the soil has been well watered by the spring rains and before seeds germinate. For frost protection autumn is the best time to mulch.
To be effective mulch needs to be applied to moist soil and be at least 5-7cm (2-3in) deep. Never mulch a very dry garden border, as any water added afterwards will tend to stay mainly in the mulch layer instead of penetrating through to the soil. In very dry weather, soak the border before laying the mulch, and work carefully to avoid trampling and compacting the soil.
How to Mulch Apply mulch about 10-15cm thick across the garden bed, taking care to keep it off the 'collar' or stem of woody plants. You need to clear away any very thick layers of mulch in spring, or you can cause overheating as the soil warms up.
If you are mulching around newly transplanted seedling in the vegetable of flower garden, allow the seedlings to be come established first. Two or three weeks after planting out remove any weed seedlings and apply the mulch. At the end of the season any straw or other bulky mulch remaining can be added to the compost heap or moved to one side and used elsewhere.
Problems with mulch Some mulch can lead to nitrogen deficiency (the first signs are yellowing leaves), especially when very fresh organic materials such as sawdust and grass clippings are used. Mixing these mulches with other organic material high in nitrogen, or adding nitrogen fertiliser can alleviate this.
Carrying a thick layer of mulch up to the stem of collar of a plant can result in collar rot and the loss of the plant. Leave a 5cm (2in) gap in the mulch around the plant stem.
Mulches that are actively decomposing, such as fresh wood chips and grass clippings, will generate a lot of heat and can scorch a plant if laid to thickly of close to a plant.
Over-mulching, applying too thick a layer, can prevent water and oxygen getting to the plants' roots where it is needed.
Birds can make a mess of mulch. Covering the mucl with strawberry netting can keep mulch in place and foil the birds until it settles and becomes a less attractive medium for scratching for dinner.
Get Mulching There are so many benefits to be had from mulching, using one of the gardener's first lines of defence in providing ideal growing conditions for plants. Mulching at the right time and with the right material will quite simply pay dividends in this season and next.
Weed cloth - make an 'X' for each plant Peastraw - good for large areas
Gravel with a contemporary look
Readily Available Mulches (contd)
Inorganic Mulches
Glass crushed rolled glass is a new mulch. Holds moisture well, quite fashionable and a very contemporary look, but not safe with toddlers who may swallow particles. Lasts well
Plastic film holds water in the soil, but lets little water penetrate unless pierced, and does not let any nutrients, water and oxygen into soil and little will thrive, lasts well.
Rock/Pebbles attractive, helps retain moisture and keeps plants stable, can take them right up the stem of the plant without risking collar rot. Lasts well.
Weed Mat It allows water and nutrients in, yet suppresses those unwanted weeds. Use with a top covering of gravel, bark or stone for a more attractive appearance. Lasts well.
