Leave the leaves is the new gardening mantra.
I immediately like it more than getting out the leaf blower or rake, bagging the leaves and finding a place to store them as they decompose into leaves. (Never mind putting them in your car and taking them to the local landfill!)
Raking leaves was the most boring task of my childhood. My mother took us all out for hours of persistent boredom.
Yet today’s ‘leave the leaves’ campaign on social media suggests that much of this work was unnecessary. Still others suggest that leaving leaves could damage your garden or even your health.
Having left leaves in my borders for 15+ years with no ill effects, I did some more research to see where we could leave the leaves and where it would be better to sweep them.
This is my central border. I’ve never cleaned leaves. Most of them rot by spring, although a few are blown onto the lawn on dry, windy days.
Can you leave the leaves on the edges?
You can leave leaves on most borders without any problems. They will deteriorate over the winter, and by spring you will barely notice them.
As they decompose, they return food to the soil.
Leaf piles also offer habitats for wildlife. People have pointed out – correctly – that this includes snails and slugs. But it also includes predators of snails and slugs, such as hedgehogs, frogs, toads, slow worms and ground beetles.
There are only two potential problems with leaving leaves on borders.
First, some trees have very thick, large leaves that take a long time to break down. The leaves of my Magnolia grandiflora can cover smaller plants, such as Saxifrage ‘London Pride’. That would deprive them of light, so I push them away (when I notice).
The photo above is my central border in the fall of 2022. The photo below shows the leaves decomposing about 3 months later. I did see a few leaf marks when I got really close, but it wasn’t a problem.
Do leaves hang around the garden if you leave them?
Many people see leaves blowing on city streets. They assume that the leaves on the edges will blow around the garden in the same way. But, for the most part, they don’t.
I have tested this in my garden over many winters. (When I find leaves on the lawn, I can tell where they came from by species!)
I’ve never known leaves to blow out the edges if the leaves are in the back, right next to a wall or fence. The wind cannot come out to blow them away. I even left a fairly high pile of leaves at the back of the border and it stayed there, gradually decaying.
However, if your border is in the middle of the garden, it is much easier for the leaves to blow around the rest of the garden. If you have a wet autumn, they will mostly stay where they fall, but in dry, sunny weather, some leaves will be blown across your lawn, paths or patios. Not all leaves will blow, but some will.
Can the leaves be used as mulch?
Yes, leaves make a great mulch.
There are two schools of thought. There are those who leave the leaves in the borders or even sweep the leaves from the lawn directly into the borders.
And there are those who advise to cut the leaves first.
Both are fine (except for those big thick leaves that need to be chopped). Shredded leaves will break down faster and are less likely to blow away.
Can leaves be added to a garden compost bin?
Yes. I often added leaves to the garden compost bin. They don’t break down as quickly as many garden clippings or raw fruits and vegetables, but that doesn’t have to matter.
Unless you are sifting your garden compost for seed planting, then having some partially composted element is not a problem. You can spread compost around the garden even if it is not fully decomposed.
However, one effective way to add leaves to your compost is to mow the leaves on your lawn. Then toss the mixed bag of lawn clippings and shredded leaves into the compost bin. It’s a perfect mix and will go bad quickly.
Here’s a really simple guide to making your own garden compost.
You can also pack the leaves separately to make a mold for the leaves. This is a wonderfully nutritious mulch for your garden edging, but I’ve found that the leaves seem to break down much more slowly when they’re all bagged up.
If you are going to collect the leaves in bags, make sure they are moist and tear the air holes in the bags. They will take at least 1-2 years to break down.
Can you leave leaves on the lawn?
This question causes a lot of arguments. Having looked at many of them, I can summarize.
If you have a lot of leaves, lying in a thick layer on your lawn, it will take months for them to break down. During this time, your lawn will be deprived of sunlight. This can cause bare spots, especially if you have a lot of thick, leathery leaves.
However, if you only have leaves scattered over your lawn, they will naturally break down, adding nutrition to the lawn.
The easiest way to deal with leaves on the lawn is to go over them with a lawnmower. Use a higher setting than in the summer when the grass is growing heavily.
You can either toss the leaves and grass clippings into the compost bin, toss them into the edges as mulch, or leave the chopped leaves where they are on the lawn. It will tear apart faster than whole sheets.
In the United States, where many lawn grasses are not native, this debate often devolves into the ‘lawns are bad’ argument.
It is important to remember that there is a difference between maintaining a non-native grassland in an area not suitable for grasslands and having a predominantly native grassland in the UK, where grasslands use relatively few resources and are both sustainable and wildlife-friendly.
You can learn more about a sustainable, easy-care lawn here.
Will the leaves cause mold when they rot?
Nature does not rake leaves. It allows them to rot, returning their nutrition to the soil.
Leaves rot on the forest floor throughout the year. Forests and woods don’t smell bad. And people are usually not warned not to walk in them because of ‘bad molds’.
But if you search whether leaves cause bad mold (mildew) online, you’ll find hundreds of warnings, almost all from the United States, about the dangers.
Mold, fungus and fallen leaves are certainly a factor in autumn. They can cause allergies, similar to pollen in summer. Some of these allergies and reactions can be severe.
But I find it strange that people are much more concerned about this in the States than in the UK.
Are our fallen leaves less likely to cause allergies? Or do some countries care more about leaves than others?
This could also be a volume issue. If you have one or two trees of different species in your garden, then you will not have a large number of leaves at one time. But if your property is surrounded by hundreds of the same deciduous trees that lose their leaves all at once, then the leaves will take longer to break down. The fungi that help break them down can be longer.
It’s also worth noting that nature doesn’t collect leaves in a big pile, so perhaps the balance of fungus and mold might be different if the leaves are in piles rather than simply left.
And not all ‘dances’ are bad…
You’re certainly more likely to see fungus in the fall, when the leaves are falling, but that doesn’t mean leaving leaves behind causes all of them. Or that they are necessarily bad.
The Royal Horticultural Society says most types of fungi are very good for gardens, helping plants take up nutrients and break down dead matter.
Their latest wildlife garden at RHS Wisley has areas where mushrooms have been deliberately planted.
There’s more from the RHS about adopting a more relaxed attitude to gardening in gardening for biodiversity.
There are several harmful fungi, such as honey fungus and verticillium wilt. But sweeping your leaves probably won’t make much of a difference to them, one way or the other.
But, as with everything, I think it’s worth an individual approach to this. Is there any scientific research being done in your area? Have you – or your family – personally had problems with leaves in the fall? What’s right for one person isn’t necessarily right for another, and if you have health issues in the fall, it’s important to address them.
These mushrooms were deliberately introduced into the wildlife garden at RHS Wisley.
Are fallen leaves toxic to dogs (or other pets)?
As I said in How to Protect Your Garden from Puppies, about 25% of any garden is likely to be toxic to both humans and pets. But most people and pets don’t eat plants.
Plant poisoning is relatively rare, but it is vital to keep a close eye on puppies, kittens and small children in the garden as a general safety measure. You never know what they will put in their mouths or what other harm they might do to themselves.
The US PDSA (People’s Disease Dispensary) says dead leaves are less likely to cause problems than green leaves.
There are several plants that are very poisonous, such as oleander or castor. I personally don’t grow for that reason either. But you will see oleander all over Europe, with lots of cats and dogs sunbathing in front of the bushes.
I suggest you ask your local vet if there are any plants in your area that cause problems with dogs or cats eating the leaves.
If you get a vague, general answer, it probably means the vet can’t remember specific cases (so there are probably few or none). If your vet has dealt with poisoning from pets eating fallen leaves or certain plants, they will make it pretty clear.
Can you leave leaves on the tracks?
Do not leave leaves on paths or places where you walk. Makes them slippery in rainy or icy weather.
But you don’t have the leaves to go far. I just rake mine with leaf rakes (currently using these Straeme leaf rakes) and put them on the nearest curb (back, against the wall!)
Please note that Amazon links are affiliate, see disclosure.
Walkways and patios can be slippery if covered with wet or frozen leaves. A friend of mine says she also slipped while walking on her lawn, so that’s another factor to consider.
Can leaves grow roots?
Leaves cannot regenerate or grow roots. You won’t find many tree seedlings popping up because you leave leaves on your borders or lawn.
Any other problems?
There’s a wonderful Instagrammer, Alexis Nicole, who says in her video, ‘Leave the leaves. They won’t break into your house and steal all your wine.’
How refreshing to find something we can all agree on. I think it’s safe to say that this is true wherever you live.
The ‘leave a leaf’ campaign is part of gardening to support wildlife. It also saves time, effort (and even a little money) for the gardener, so it’s a ‘win/win!’
But, as with everything, there is no ‘one-size-fits-all’ in gardening. If you’re not willing that this will work for you, maybe try leaving the leaves on one border and see what happens.
Let me know how you found it.
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