Autumn Leaves…

…and returns the following year. It is at this time of the year when people start their bonfires. Whenever I see someone burning a heap of leaves, it evokes in me the same sort of emotions as would, say, the sight of seeing somebody setting a match to a pile of bank notes, or worse still; books. Not only is it contributing to our polluted atmosphere but it’s a terrible waste of a valuable resource.

What, in effect, this is doing is robbing nature of one of her most valuable assets. Deciduous trees shed their leaves for a very good reason; these bits of organic material rot down and return to the soil, replenishing nutrients that may have been washed away by rain or used by the tree

Dead leaves in quantity rot down very quickly, some faster than others and the end result of this sort of compost is called leaf mould. Leaf mould is one of the best of the soil additives known to gardeners, not only as a soil conditioner but it can be used also as a potting compost.

About two decades ago, I was privileged to find myself working on the restoration of the now famous “Lost Gardens of Heligan” project (with a team of volunteers; a cheery and boisterous band of various enthusiasts from around the locality*), as part of a horticultural course I was taking at that time.

(*what I like to recall as The Lost Hooligans of Gardening)

These enigmatic and somewhat mystical gardens, situated on the south coast of Cornwall in the south west of the British Isles, had been all but forgotten and neglected since the First World War and the project to renovate it was an enormous undertaking. The story of Heligan could and may well be the subject of another article but numerous books and TV series have been produced about this fascinating place.

Heligan’s purpose for the time being is on the subject of leaf mould. At the time of joining the team on this exciting project, we were attempting to unveil the many miles of hidden winding paths and walkways that meandered through the 300 acre site. The reason they were hidden is because they had been buried under nearly 100 years of accumulated leaf mould.

This task was made difficult because of lack of information as to where these paths were and not being able to utilise mechanical diggers for fear of disturbing the surrounds. For the most part, this covering of leaf mould averaged 18 in. in depth; quite an amount overall, as you can imagine.

I want to make a short pause here just to go into some detail about the break-down of various types of leaf. The leaves of trees such as Sycamore, Ash, Birch and other fast-growing examples tend to rot much faster than those of the majestic and venerable old timers like the Oak and the Beech.

At the other end of the scale, you have the leaves of evergreen ornamentals in the form of Rhododendrons, Camelias and Laurels, which take, well, years to de-compose. As most of the planting at Heligan Gardens consisted of the latter, plus a scattering of mature Oak, you can appreciate the quality of nearly a century of nature’s work in the transformation of these arboreal droppings.

With the consistency of commercial compost, this well- matured pitch-black substance was the equivalent of a horticulturalist’s diamond mine or “Gold Leaf” might perhaps be considered a more appropriate term.

And there was literally tons of the stuff!

Tim Smit, was the visionary mind behind the Heligan project and someone for whom I have a great admiration and respect for, not just for his grim determination and tenacity in the face of seemingly over-whelming odds; not to mention a shortage of funds (I was just one of about a dozen volunteers at this stage) but for his sincere warm-heartedness.

After a bit of negotiation – and a few pints in the local inn – he kindly agreed to my loading up my little trailer from time to time (volunteers’ perks, I think we called it), with this marvellous stuff in order inject some life into my hill topped, wind-swept and rather exposed garden.

It was after that point that I took more than a passing interest in the benefits of leaf-mould…