There are many sources that tell you that composting bindweed, not just bindweed but all perennial weeds such as couch grass and dandelion is a bad idea. It’s really not true, these will rot down just as well as anything else if you give them time. How I see it is that I’ve spent time making my soil perfect for growing what I want and these thugs are stealing all the goodness, I want it back and and I’m going to make damned sure that I get it! There are several ways of doing this that I’ll go through here but essentially it’s a waiting game, the rewards of which are well worth time.
Making comfrey tea is widely accepted as a good source of nutrients for your plants, the leaves are high in the minerals that plants need to grow, especially cultivars like Bocking 14. But they’re not so much better than other plants that make using your weeds an unviable option. Just do the same as you’d do with the comfrey but with the bind weed, dandelions for potassium and especially nettles for a bit of a nitrogen boost. You’ll need a big container to do this in if you have anything like the quantities that I was dealing with earlier in the year, thats why I opted for going down the composting route.
I’m not great at making hot compost, I’ve tried and I will keep trying until I get it right but for me it’s making sure that I have the space and letting things decompose in their own time. I’ve still been composting bindweed for years. If you can get your compost up to a decent temperature then you’re not only a better gardener that I am but you’ve got no excuse not to be keeping the weeds for you own benefit, remember that the’ve stolen from you. Simply put, if you exclude all light from the weeds then they are going to die, that’s it, no plants can live without light.
The first lot and most convenient was to bag it up in old compost bags, just stuff it all in roots, soil and all. After 5-6 months you’ll find that there is just decomposed matter left that can be spread over your beds again. If you’re concerned that there might be something living in there then run it through a course sieve and you soon see. When I dug mine out there was one bag that had some particularly stubborn roots in it, I mean really big ones that were still there, this one just went back on the pile for another day.
The rest was put in a composting bin and covered with a weed fabric that blocked the light from it. These bins have paving slabs on plastic sheet at the bottom as if you place it on the soil those weeds will find a way down and out. Also the sides have no gaps, if they do then just lay a sheet of weed fabric down and wrap it all up like a present that you can open a few months later. If you see any growth making a bid for freedom then just break off the growth, it will soon give up trying.
Unless you’re really vigilant in removing the soil from the plants as you pull them up and with couch grass this is hard, then you’ll get a loamy sort of finished result. Just remember that this had all of that living material broken down in it, it’s perfect for laying over cardboard for a no dig solution. I have 1 cubic metre of it now, that covers quite an area. As you can see from the last picture it’s now rejuvenating a shady bed that was particularly hit by the drought.