I have lots of bagged wood chips about six months old. Can anyone tell me how long I need to let them compost before digging in to my veg patch? I want o bulk up the soil but I've heard that digging new wood chips into soil, leaches out the nitrogen and weakens or kills plants.
The quantities of nitrogen involved are really quite small and you can compensate by adding pelleted chicken manure at planting time. However, chipped bark can be quite chunky and can take several years to break down into a soïl improving humus so you're better off digging in well rotted garden compost and leaf mould and maybe using the chipped bark as a weed suppressant mulch around soft fruits such as blueberries, gooseberries, black and red currants or raspberries and blackberries.
The RHS recommends composting for at least 12 months.
What are the woodchips? Are they from a garden shredder, a bag from the GC or woodworkers shavings
It also really depends on size. We've had wood chips for paths at about 4" size cos they don't blow away and they take years to break down. Also soft wood such as pine will rot faster than hard wood but, according to my suppliers, different kinds of pine rot at different rates. Beware also of any chemicals in treated wood that has been shredded as they contain préservatives and fungicides you don't want to be feeding to edible plants.
Thanks everyone for such prompt replies. The chippings are shredded from boughs and branches of a couple of trees we had to fell in our school garden. They were alder and cherry and they're about 1 - 2cms in size.
No worries then but leave them another 6 months and then see what size and consistency they are.
If you sprinkle some pelleted chicken manure into the bags, give them a good mix and dampen them, the woodchips will rot down much faster than if left to their own devices. Make sure the bags have a few holes in the bottom so that any excess water can run out.
Professor of Horticulture, Linda Chalker-Scott is a huge proponent of wood chip mulches--unaged. She writes The Informed Gardener and a column with other professors of horticulture which scientifically test the many things we are told about gardening. http://puyallup.wsu.edu/~Linda%20Chalker-Scott/Horticultural%20Myths_files/Myths/Wood%20chips%202007.pdf But it depends on what you are using them for. She doesn't recommend them for annuals or things with short root systems.
I put mine straight on the garden in winter and it's great for holding in the moisture. I don't spread them on dry soil, they'd hold the moisture out