Please compost your weeds
There seems to be a lot of confusion about composting weeds. Weeds make up the main part of my compost heap and they really make excellent compost. Yet on numerous occasions I noticed that people start dumps – of unwanted or undesirable materials. There is one community garden I work at and this year my lovely New Zealand Composting Box didn’t seem to fill up. Only last week I found out the reason – all those beautiful weeds were dumped in a large heap (a lot larger than my compost pile) behind a hedge alongside blighted potato leaves. As you can imagine I was quite upset and queried the case and the answer was: “Oh I thought we couldn’t compost weeds!”
So just in case more gardeners think that weeds can’t be composted let’s clarify the situation -first with a philosophical viewpoint and then with a more practical advice on what can and can’t be composted.
Everything that has grown in your soil has taken up nutrients – this includes the vegetables that we eat as well as the weeds that grow. If we were to dig in all the plants that grow there would be the same quantity of nutrients left before and after. Unfortunately (or fortunately) we take the vegetables away and eat them so already we have a net loss of soil fertility. So at least we should return the weeds back into the soil either through hoeing on a sunny day and leaving them to decompose on the ground or through composting.
Alright I accept that certain weeds can’t be composted otherwise you spread them all over the garden. These include the roots of:
- Scutch grass
- Ground elder
- Bindweed
- Japanese knotweed
We should also avoid putting in weed seed heads from most weeds as a normal composting process will not achieve hot enough temperatures that would kill them.
Otherwise please compost your weeds.