7 Ways Smart Gardeners Use Autumn Leaves to Nourish Their Plants

Most people see fallen autumn leaves as a nuisance to get rid of – but they are literally a gift from above to nourish your garden!

There are so many ways you can turn this glorious autumnal abundance into something absolutely invaluable, from making a potting mix that’s ideal for starting off seedlings to using them to make the very best garden compost, feeding the soil – and the worms within – with lashings of lovely leaves, and even using them to store root crops.

How to Make Leafmould

Let’s start with my absolute favourite way to use leaves: making leafmould. If you’ve never made it before, this is quite simply some of the best stuff you can put into a garden, and it costs nothing but a little patience.

Mature leafmould, made from nothing more than collected leaves piled up and left to slowly rot down, is a beautiful thing: dark, crumbly, and smelling like a woodland floor. This stuff is really fabulous because it’s a stable and fairly low-nutrient organic material, which is just what we want when we’re starting off seedlings. It’s great for building soil health too. It typically takes about two years to make (but don’t worry, I’ll also share ways we can use leaves right now, without having to wait!).

Making a seed-starting mix with leafmould is easy, and it will save you a pretty penny given the rather steep cost of commercial blends! Sieve it to remove any lumps and give a finer texture, then simply mix one part leafmould with one part of composted woodchips, garden compost – again, sieved – or horticultural or sharp sand. This beautiful blend can now be used for filling pots or trays for seed sowing.

So how do we make our lovely leafmould? The easiest way is by setting up a simple cage by hammering four sturdy posts into the ground to mark out a square of around a metre (3 feet) each way, and wrap wire mesh all the way around and secure it to the posts with staples. It’s so simple but so effective.

Then just pile in all of those diligently collected leaves. The mesh keeps them all contained and, importantly, allows plenty of air circulate, which is exactly what we want. If the leaves are dry, give them a really good soak as you go, because you want them damp all the way through, kind of like a wrung-out sponge.

And to help kickstart the whole process, if you have any garden compost or leafmould from elsewhere in the garden, you can make a hole in the middle of your leaf pile and then add that in there – especially if it has lots of worms in it. Or simply spread a layer of finished leafmould or compost on the ground before adding your leaves. This will help to inoculate the new pile with all sorts of beneficial composting organisms for the very best possible start.

Alternatively, you could just pile leaves into a bulk builder’s bag, or if space is limited, bung your leaves into a plastic sack (or a burlap or hessian equivalent if you want to avoid plastic). Tie it off at the top then stab some holes across the bag (if it’s plastic) to let in that all-important air. Pop it somewhere out of the way and that’s it – you can just let it do its thing.

Leafmould does take its time. This isn’t a quick job. And that’s because fungi rather than bacteria are doing most of the work here, so expect to wait around a year for something rough and ready – perfect for mulching growing areas with – and nearer two years for that truly beautiful mature leafmould for making your own seed-starting or potting mixes.

The Best Leaves for Making Leafmould

Most leaves make great leafmould but, it has to be said, some are better than others. The best leaves include pretty much any from deciduous trees and shrubs such as beech, birch and hazel, though expect thicker leaves like horse chestnut to take a little bit longer.

Leaves I would steer clear of include black walnut, eucalyptus, leylandii and cherry laurel, as these can release chemicals that inhibit growth, and I’d avoid anything gathered from busy roadsides, which may carry pollutants. Conifers and thick glossy leaves like holly will be very slow to rot down too. Pine needles aren’t great, but they do make for excellent ‘pine straw’ to mulch around garden shrubs.

Mulching with Leaves

The second classic use for autumn leaves is as a mulch – simply covering the ground with your leaves. Just rake a generous layer of leaves straight onto any bare beds you’ve got.

As they slowly break down over winter, worms and other soil life will drag them under and turn them into gentle nourishment for your soil. Nature’s literally doing the digging for you. Yet another reason to love those worms!

To stop them blowing away on a windy day, at least initially while they’re still quite loose and fresh, lay a criss-cross pattern of bamboo canes, some wire mesh, or even horticultural fleece over the top of the leaves. It works a treat. Or you could just water them to weigh them down into place.

Come spring, you’ll find soil underneath that’s noticeably softer, richer, and just itching to be planted! Any leaves that haven’t fully decomposed can simply be raked aside and thrown on the leafmold pile or the compost heap.

Composting Leaves

Leaves are what we call a ‘brown’ ingredient for composting, because they are rich in carbon. They’re brilliant for balancing out all those nitrogen-rich ‘greens’ like grass clippings and kitchen peelings.

If your compost has ever turned into a soggy, smelly mess, mixing in dry leaves is very often the fix that’s needed.

Storing Roots in Leaves

If you’ve got carrots, beetroot or parsnips still in the ground, you’ve probably heard that digging them up and packing them into boxes of damp sand is the classic way to store them in regions with hard winters where the ground freezes solid. But sand can be a real hassle to source, heavy to lug about and, to be frank, is a bit messy. But dry leaves work just as well, and they’re sitting right there in your garden for free. It’s almost as if nature sent us these leaves just in time for harvesting and storing roots.

Dig up your root crop then twist off the foliage, leaving around inch or so of stalk. Don’t wash the roots – just brush off any loose clumps of soil. Lay a couple of inches of dry leaves into the bottom of a crate or box then arrange your roots on top, make sure they don’t touch each other. Cover them over with a layer of leaves, and repeat until your crate is full.

Store your crate somewhere cool, dark and frost-free, and be sure to check on it occasionally, and use up immediately anything that starts to soften. Stored this way, a harvest of roots should keep for months.

Protect Tender Plants

The insulating effect of leaves works beautifully for anything in a pot that’s only borderline hardy. Cluster the pots together somewhere sheltered, then pack leaves between and around them right up to the rim. You could use a ring of wire mesh to hold the leaves in position. The trapped air acts just like a duvet or comforter, buffering the compost from the worst of the frost.

Do the same around a cold frame, or even against the coldest side of a greenhouse, for a genuinely effective, entirely free layer of extra protection – perfect in really cold regions with frigid winters. Just remember to pull the leaves back in spring so things don’t become damp and slug-ridden underneath.

Make a Wildlife Leaf Pile

Here’s one close to my heart. Tucked away in a quiet corner, a loose pile of leaves becomes a lifeline for all sorts of garden creatures over winter: ladybirds, queen bumblebees, moths and butterflies, hedgehogs, frogs and toads – you name it!

Ladybirds cluster together in leaf litter to ride out the cold, ready to tackle those nigglesome aphids come spring. Queen bumblebees often burrow just beneath a leafy covering for warmth. Moths and butterflies of all sorts overwinter tucked inside curled-up leaves, and larger visitors like hedgehogs, frogs and toads will happily use a leaf pile as a place to hibernate or just shelter from frost.

Unlike a tidy leafmould cage, this pile should be allowed to stay loose and a little wild. Just bank up leaves to a good depth in an out-of-the-way corner then leave it alone until well into spring. It’s a small thing, but it makes a real difference to the other creatures that call your garden home.

Mowing Leaves into the Lawn

And now for the easiest use of the lot! If you’ve only got a light scattering of leaves across the lawn, you don’t need to rake them up at all. I just ‘leave’ most of mine where they are. But to help them break down I like to run the mower over them without the collection bag fitted. The blades shred the leaves into small fragments that settle down between the grass blades, feeding the lawn as they break down.

Only do this with a light covering of leaves. If they’re piled thick, it’s better to rake it up for one of the uses we’ve already covered. Mowing thick piles can also risk damaging more delicate lawnmowers, and there’s more chance of harming insects and other animals that may have already bedded down in them for winter.

Incidentally, only ever collect up and remove leaves or grass clippings from the lawn to use as a mulch on my vegetable beds – the rest is left to rot down where it falls on the lawn. The result is a far richer soil, which in turn supports a much more extensive root system for all these lawn plants. It means that when we experience a summer drought, my lawn stays green for a lot longer than many neighbouring, closely cropped lawns devoid of their clippings.

When you stop to think about it, it’s truly wonderful that something as beautiful as autumn leaves is also so useful. Leafmould for your soil, mulch for your beds, warmth for tender plants, a winter sanctuary for wildlife, and even a home for your harvest – all of it free, all of it just waiting to be raked up!

Let me know in the comments how you plan to use this fabulous autumn gift in your garden, or if you’ve got a leaf trick of your own I haven’t mentioned.