Leaf Mould

Made a start on plot 5 today. Down at the bottom where it tends to get waterlogged in wet weather, I've some raised beds. Now although I'm not a huge fan of raised beds, the fact is that when your plot is a bit out of control, you can attack a bed at a time and feel you're winning.

One bed is devoted to asparagus and this is a difficult crop to weed. It's got shallow spread roots and hoeing the roots or worse still, the crown, is not the best way to grow it!

The soil in the bed wasn't the best quality and seems to have reverted to being clayish so it was a little difficult to hoe, especially as weeding next to the crowns is a hand job.

Once cleared and the soil surface broken up, I gave it some fish, blood & bone to help it with spear production and then mulched with an inch of leafmould. Leafmould is one thing that is really under rated in the gardening world and I've heard some nonsense about making it.

Unlike compost which benefits from heat and being turned to promote microbial action etc, all leafmould requires is time, a little moisture and air. Leaves in the wood fall to the ground and gradually decompose without any additions.

Adding compost activator or extra nitrogen will not speed up the decomposition of leaves into leaf mould. The only thing you can do to speed up the process is to break the leaves into smaller pieces. Those leaf vacuums that mulch them at the same time are great for this.

We get our leaves dropped off in huge piles by the council, so that's not really an option. I pile them up in a wire sided cage and forget them for a year at least. Actually, if you can, two or even three years is better.

Leafmould has no nutritional value. If you think about it, the tree sucks all the goodness back out of the leaf, which makes it turn to those gorgeous autumn colours, before allowing them to fall to the ground.

What leafmould does have is a fabulous structure, very much like peat. So it makes a great soil conditioner, opening clay soils and binding sandy soils. It holds moisture but allows drainage and makes it a lot easier to work heavy soil.

The texture is ideal for making your own potting compost as well, just like peat but a very renewable resource. As I said, leafmould has no nutritional value but you can add it in. One good trick is to layer lots wilted comfrey in layers as you build up your leaf mould pile.

If you do that, the comfrey adds a lot of nutrients but not too much nitrogen and after a year or two you have a great seed compost. Because the rain will wash out the nutrients, cover the bin with some plastic sheet or suchlike but do ensure the pile remains damp.

You can make leaf mould on a smaller scale – just put the leaves into black plastic sacks, poke some airholes in the sacks and add some water if dry. Stick the sacks somewhere, perhaps the shaded place behind the shed where nothing grows anyway, and leave for a year.

Do be aware that the leaves shrink down an awful lot – my five foot high pile of densely packed leaves ended up a foot high.