How to mulch garden borders

Inspired by a trusted UK gardening guide. This walk-through draws on the popular BBC Gardeners' World video "Monty Don's Essential October Tasks To Do Before Winter", which covers autumn border work including mulching - one of the UK's most-watched gardening channels and a reliable source of seasonal advice for this climate.

1. Pick the right time of year

Autumn is the main mulching season for most borders. You want to apply mulch when the soil is still warm and moist from summer - typically September through to November in most of Kent. Do it before the ground gets cold and hard, but not on frozen or waterlogged soil.

Spring is also a reasonable time, just as things start growing. Either way, avoid mulching in midsummer when the soil is baked dry - you'll just be locking in the dryness rather than the moisture.

2. Clear the border first

Pull out any weeds before you mulch. Mulch suppresses weed seeds from germinating, but if there are already established weeds in the border they'll grow straight through it. A thorough weed now makes the whole job more worthwhile.

Also cut back any dying annuals and tender perennials that won't survive winter. If you're leaving hardy perennial stems for wildlife interest, that's fine - but clear out the dead material that will just rot under the mulch and harbour slugs.

3. Choose your mulch material

Garden compost is the best all-rounder - it feeds the soil as it breaks down and costs nothing if you've been making it. Well-rotted manure works in the same way. Mushroom compost is good if you can get it, though it's alkaline so not ideal for ericaceous plants like rhododendrons.

Bark chippings or wood chip are slower to break down and better for suppressing weeds between shrubs than around herbaceous plants. Leaf mould is excellent and again costs nothing except a bit of patience. For tender plants you want to protect from frost - things like agapanthus or tree ferns - bracken or straw works well as a temporary insulating layer.

4. Apply at the right depth

Aim for around 5 to 7.5 centimetres. Too thin and it won't suppress weeds or hold moisture effectively. Too thick and you can create conditions that encourage stem rot, especially on plants with crowns at or near soil level.

Spread it evenly using a spade or garden fork to distribute, then work it over with a rake to level it out. You don't need to dig it in - let worms and soil organisms work it in naturally over the coming months.

5. Keep mulch away from stems and crowns

This is the most common mistake. Leave a gap of at least 5 to 10 centimetres around the base of each plant, especially shrubs and perennials. Mulch piled directly against stems traps moisture and can cause rotting, particularly over winter when things are wetter and colder.

Around trees and shrubs, the same principle applies - keep it a handspan clear of the trunk. This also stops rodents nesting in the mulch right against the bark and gnawing at it.

6. Work through methodically

Start at the back of the border and work forwards so you're not stepping on freshly mulched areas. Tip barrowloads at intervals along the border first, then spread, rather than trying to wheelbarrow between plants as you go.

For a large border it can help to do it in sections on separate days. The mulch will still do its job if the application is a bit uneven to start - it settles and evens out over time.

When to call a handyman

Mulching a large garden or allotment can be heavy going, especially when you're shifting several barrowloads of compost or bark. Richard can help with autumn garden tidy-ups across Sandwich and East Kent - clearing borders, applying mulch, and getting beds ready for winter in one visit.