What to do with the leaf litter?

We've had so much interest from people wanting to know what can be done to help their conker trees. So, at the beginning of 2011, we extended Conker Tree Science so that people could help us find out if clearing leaf litter really does help reduce the amount of damage on a tree. And the answer appeared to be a clear  'yes'.*


So, if clearing leaf litter is worth it, then what should be done about it?


Firstly, it is worth noting that general leaf litter is a fantastic ecological product that allows the recycling of nutrients and provides shelter and food sources for a wide range of animals, plants, fungi and all other sorts of microscopic creatures.


But, the horse-chestnut leaf-miner overwinters in the leaf litter and emerges in the spring to attack the leaves of horse chestnut trees.


Nigel Straw and colleagues at Forest Research produced a report showing that to effectively kill the moth pupae it is neccesary either to:

1. Cover the leaves in a layer of soil to stop the adult moths emerging. To quote from the Forest Research website, you will need to "cover the leaves with a 10cm layer of soil or 15-30cm layer of other plant material, and leave the heaps undisturbed until the end of May".
2. Compost the leaves at a high temperature. (The easiest way is via a commercial composting scheme, e.g. through your local council.)
   

Once the leaf litter is well rotted (so at least a year old, once all the moths have died) then it should be safe to use as normal compost.

* Why do we say 'appeared to be' and not 'is'? Well, the answer is because the formal statistical analysis of this is still on-going. We'll have the answer soon.