How To Make Leafmould

Make Leafmould Yourself

Raking up leaves is part of a gardener's life. Sometimes the volume is overwhelming, and there is nothing to be done except burn them, or bag them up as green waste.

But the best options are to keep those leaves and use them as mulch, compost, or leaf mould: that crumbly, airy, free draining stuff that improves soil, and makes a superb potting medium for seeds and cuttings.

All leaves and conifer needles will make leaf mould eventually.

• The fastest to break down are smaller and/or thinner leaves like beech, oak, hornbeam, ash, birch, cherry, elm, lime, poplar, or willow.
• Thick, big leaves like horse chestnut, sycamore, maple, or magnolia, and also tough little hawthorn leaves,  or any evergreen leaf will take much longer to make leaf mould; they should be shredded first to speed things up. They are better for mixing into a normal compost heap, so use them if there is nothing else.
• Pine needles take years to break down, so aren't usually a practical choice for leafmould.

The larger leaves are not bad, they just need more time or effort, so it makes little sense to use them unless there is nothing else.

If you don't have masses of leaves for a big pile, the simplest thing is to bag them up in old compost bags, bin bags, etc.

• The leaves should be damp
• Pack the leaves into the bag quite tightly but without ramming them in
• Tie up the mouth of the bag, then stab it a couple of times to allow some air to circulate
• Tuck the bags away somewhere out of sight
• After a year or two, you will have the most brilliant leafmould

Gardeners whose leaf output is too much for a few black bags should build a leafmould container somewhere out of the way. Ideally, leave room for another to fill one while the first rots down.

• Use four or six tall stakes depending on whether your feng shui demands something rectangular or square.
• Make a wall out of chicken wire tied to the posts: use wire, as it lasts longer than string
• Keep the posts outside the wire. As the weight of leaves increases, it will push the wire onto the support posts, rather than tearing it off them.
• Line the bottom with a bit of Mypex so weeds do not grow up and through your leafmould.
• In a hot dry summer, moisten the pile occasionally to speed decomposition.

Which leaves should I leave out of my leafmould?

Most leaves are fine for leafmould (if time is no issue), but there are few that are better to avoid:

1. Evergreen leaves (e.g. holly, laurel, conifers)

These are too slow to decay, and are best consigned to the compost heap, unless you shred them first. 

2. Fruit tree leaves

This is a precaution against diseases like Apple/Pear Scab and its friends (various rusts, leaf spots, and blights) are just too common an affliction on fruit trees to risk composting leaves that may well be infected.

Leaves from fruit trees are best disposed of by burning, or composting in a pile that won't be used near them, or rose bushes (see next point).

Almost all fungal diseases that attack leaves have a life cycle where their spores overwinter in leaf litter beneath the infected tree. With spring and warmer days, rising air currents help the spores back into the tree to re-infect it. As a spore can survive for years until conditions are right, a leaf-heap would provide ideal overwintering conditions.

3. Rose leaves

The rose family includes most of the fruit trees grown in Britain, and they can share diseases.
For the same reasons as above, rose leaves are best burnt, or composted & used away from other roses or fruit trees. 

Other Benefits of Leafmould

Removing leaves from lawns and beds deprives slugs and snails of nice hidey places to pass the winter months. Dealing with the leaves is a way of preventing infestations of these, the bane of all gardeners, and reduces your spend on slug pellets - an all their nasty chemicals - next year.

Leaves left to rot on paths make them slippery and over the years will accelerate your need to repair them.

Leaves left on lawns will ruin the grass beneath them.

So enough of the jaw-jaw.....off with you and your rake, smartly into the garden.