Wood Chippings in the Soil
by John Harrison on Wednesday, 11th May 2011London
I'm writing this in London where work has taken me for a couple of days and it couldn't be more different than home in north Wales. The noise is the first thing that shocks. Still, the sound of the airplanes going over drowns out the noise of the tube trains. Then it's the huge buildings, crowded streets, traffic and so on, which are another shock after the countryside.
Being down south, or 'sarf' as the native say, I'm aware of how far ahead of us they are. The trees and flowers are a good two or three weeks advance. This north south weather thing has always been but this east/west, dry/wet divide seems to have come recently and it's getting worse.
Had an interesting chat with a cabbie, he'd actually got a copy of my book and said it had helped him (Hello Mike!!) One thing I hadn't quite realised was how dry the south east has been. It's like we have two countries now; the wet one and the dry one. It's easy to forget, sometimes I get emails after I've moaned about too much rain basically telling me how lucky I am.
Wood Chippings
I had this interesting question in by email and thought it worth sharing.?
“ I have recently had 3 dead trees chopped down on my lawn and have had the stumps grinded. The chippings are of course mixed in with the soil . I want to seed over the patches left but can't remove all the chippings/soil as it goes too deep. Do I have to leave it for a year before re-seeding the now bare areas left by the trees? Help would be appreciated.”
The wood chippings will, if left to their own devices, rot down producing beneficial humus in the soil and improving it. It's the rotting down process that's the problem. Whenever we compost something we have two components, the carbon and the nitrogen. If they're in balance then things go well but out of balance the rotting down will slow or may even stop.
Wood is obviously carbon so it will seek nitrogen to rot down. This nitrogen will be stolen from the soil and so, until the wood has turned into humus, not available to grass or other plants. The answer is really quite simple, add nitrogen to the soil to compensate.
The cheapest and, in my opinion the simplest way, is to use a high nitrogen fertiliser such as sulphate of ammonia or prilled urea. I'd go for about 50 grams of sulphate of ammonia or 25 grams of prilled urea dissolved in 5 litres of water and spread over a square metre. It really does depend how many chippings there are in the ground. Really thick and you'll probably need more nitrogen.
Allow a week or two for things to calm down and start getting into balance and you should be able to try re-seeding.
If you'd rather not use artificial fertiliser, then you can use dried blood which is an organic fertiliser to correct things, use about double the amount as you would sulphate of ammonia.
Another thing to be aware of with lawns is the pH level. Grass demands a lot of nitrogen and our feeding this increases the acidity of the soil. Some lawns are fed well every spring and summer but never see any lime. A good application in the late autumn, early winter will do them a power of good.
