Fallen leaves as border "mulch"?

Anna33

We've got heaps and heaps of leaves that have fallen due to the trees in the copse the other side of our garden, which I'm quite happy about as I plan to start making leaf mould. However, there are a LOT of leaves...!

Is there any benefit to me piling them up on the borders as well, in place of a more typical mulch? I kind of figured that it would be both insulating and would eventually rot down, perhaps when I put on a spring mulch next year.

Or will it do nothing but smother what is in the borders already (mostly perennials, some shrubs)?

Loxley

I would be worried about a thick layer of whole leaves becoming a bit of a 'blanket'. Shrubs won't mind, but some perennials and bulbs might struggle to push through. If you can chop the leaves up e.g. run a lawnmower over them, it will make them less liable to smother, and will speed up the process they are broken down into the soil.

Pete.8

I agree with Loxley.
It also depends on they type of leaves.
I have an big acer in the front garden. All the leaves have now dropped beneath it and they are 2" to 6" thick on the ground. By spring most will have largely broken down as they are quite delicate leaves.
My neighbour has a big oak in their front garden - by spring the fallen leaves look just as they did when they fell as they leaves are quite thick and waxy.
I do use the oak leaves for leafmould, but they take several years to break down.

Palustris

It also depends on how many worms and woodlice you have. Here there is a distinct lack of either and so even thin leaves stay pretty much the same as they were when they fell. I have a lot of Cyclamen seedlings just beginning and where they are covered in leaves, they become very etiolated unless I remove the leaves.

Also here the leaves tend to be blown off the soil and onto the paths which then become slippery as the leaves get wet.

I think it is a matter of knowing your conditions and then deciding whether to remove or leave.

Fairygirl

I'd agree. It depends on the type and the amount, as well as location, and type of  planting.
I have leaves in various parts of the garden, blown in from the neighbouring maple. They won't do any harm where they are - at the foot of the hedge, and a border with mainly shrubs, and a few tough plants.  If I had a bed of airy fairy perennials and bulbs, or something like the cyclamen mentioned, and it was many inches thick, that would be different. 
I've just collected a load of oak leaves from a neighbour, and I shredded some with the mower. They're now round the base of some shrubs. 

Palustris

I also should mention that the fallen leaves give a safe home for a multitude of slugs.

I have just collected up 20 barrow loads of leaves and put them in the leaf mould pile. There are still lots left on the soil, these were just the ones which are too thickly layered to ever rot down.

Posy

I was going to mention the slugs! Fallen leaves are an excellent place for them to shelter and later, breed. If you have a slug problem your leaves are better collected up.

Topbird

I agree with all the previous postings🙂

I have one large, slightly wild, woodlandey border where I leave a thick (4") carpet of ash and other soft leaves to rot down naturally every year. I've done that for several years without any problems. However, there are only tough trees and shrubs and tough perennials growing in that border. There are quite a few cyclamen, muscari and tete-a-tete bulbs and the leaves don't seem to cause any problems for them - I'd probably do more harm trying to rake the leaves off. I have never had a problem with slugs or snails in that border (famous last words!!) but I do collect leaves from other borders where slugs enjoy dining out.

Shrubs will be fine with leaves underneath them and perennials which die right back in winter (geraniums, hostas etc) should also be ok (they are in my garden anyway). Alpines and other small evergreen perennials would struggle if they were covered in leaves for a prolonged period. 

Ysera27

I leave them. The blackbirds are always turning them over and scratching about so I think they eat the slugs etc. 

Palustris

I wish they did, but last year we found hundreds of slugs on the parts of the garden where we left the leaves. I use a leaf gripping thing to pick up the leaves. It ,so far, does not seem to damage the foliage of the plants. The area I have cleaned so far (20 big barrow loads) has a lot of evergreen leafed plants in it and they are buried under4 to 6 inches of leaves. Or at least they were, now they are in the light and still have a thin mulch of leaves on the soil round them.

At least we keep the leaves. The previous owners here apparently collected them up and took them to the Council Refuse centre.

Anna33

Ah, thank you all, I think I'll have to move them off in the near future then, as most of them are oak leaves, and from the sounds of it won't actually rot down much in the short term. Not sure I can realistically cut enough of them with a lawnmower as there are so many of them - which is not a complaint, I get the joy of having trees and all the birds that come with them next to our garden for the rest of the year, so a few weeks of leaf collecting is a small price to pay.

Interestingly, where I had left a heavy layer over a patch of as yet uncultivated part of the garden (my Spring project), something big has snuffled through them and dug up loads of soil underneath them. Am thinking a fox, as they also knocked over some of the logs lining the hedgehog hole I made in the fence, and was too much damage for birds or other small mammals. Have ruled out badgers as there is no way they can get in to the garden though.  I hope they found enough beasties to make it worth their while!