Composting

Lewisium

So I do my own composting at the allotment but my issue is it takes so long to break down and running out of space to put any waste. I'm upto 3 bin bags for the skip now. My composting method is I put in weeds / spent veg plants etc & then strip down some cardboard into smallish pieces and put that in with it. Then I sprinkle on some garotta and water it in. I've since heard straw is a good idea too. It's an enclosed composer so should be to keep rats out. I have 2 other big metal grid composters that I inherited too that are brim full but no way to get any compost out of the bottom, no door to open. Is there any other advice I could get?

Posy

Well, there are many compost experts on here - not me! - who will advise but I make excellent compost and I believe the key thing is to turn it regularly. I prefer open heaps which get air and rain, but I don't have a rat problem. I chop up dry material and add grass cuttings and fill a bay. Then, I pull the lot out, mix it up like a Christmas pudding and pile it into a second bay. As often as I can, but at least two or three times, I turn it back into the bay it formerly occupied, breaking up lumps and mixing dry and wet bits. It works a treat. I don't achieve temperatures that kill weed seeds but that isn't a problem for me.

Lewisium

I'm tempted to stick a thermometer in to see what temperature It gets to, I doubt its very hot, although straw should help. My compost bins are full to the brim so turning it is difficult. Wish I could hire someone to empty my composters and start again now. 

Wilderbeast

@Lewisium straw will add browns to the mix, if you want to speed things up you need more greens so grass clippings, fresh manure,lots of green leaf material etc. If you can lift the wire cage bins up you can turn the compost by forking it back into the empty bin, a good time to add lots of grass if the heap isnt well rotted. I make lots of compost theres no secret you just need loads of material and being prepared to turn the heap lots. Although i have my bins very hot i only take compost out of the bins once a year in early winter, all late autumn material has an entire year to compost while as the year warms up material takes less and less time to compost. All summer grass (i collect this from neighbours as well), veg waste,  very leafy tree surgeons mulch and fresh manure gets so hot and remains so for for several weeks when turned regularly that i can produce excellent compost in 3 months. For my system keeping my compost wet enough is the hardest part as all the heat means that they steam loads of moisture out of the bins, i did used to cover the heaps with plastic and carpet but this really encouraged the rats to move in so i now leave the tops open and the rats stay away.

Lewisium

The metal cages are open to the elements. I have an extra 65L small plastic composter with lid too. The metal cages are chocablock full and probably 2m x 2m and weigh a bit, and have been since before I got the allotment, I'll try turning it more and adding straw. It's prob 80% green manure in them. 

Fire

I would experiment with finding a basic composting bin system that really works for you - something that offers easy access to turn and empty. Some people use big dumpy bags, some just have piles, some people use dustbins or wire cubes that you can just lift off. Or wooden bins where the sides can be removed.

You would need to look at how your current compost is getting on - is it too dry and crispy or wet and soggy? Something is up if it is taking so long to break down. How long if your cycle? If too dry, try cutting plant material up smaller and adding fresh grass, if you have it.  If too dry, try adding wood chip. Straw can take a longer time to break down. The more you turn it, the faster the compost decomposes, if the ingredients are right. It might not be a great idea to put in perennial weeds.

Fairygirl

I think you need a bit more brown from the sound of it, so if you can manage that, it'll help. Things like cardboard and newspaper [or similar] are ideal. I put all the egg boxes in. Keeping moisture in as well is beneficial.  The greens heat up but if you can't turn easily, it can become solid and sludgy.
Turning and getting air in is certainly the best way, but it isn't always easy to do. I don't have room to empty mine and turn them either, so I have to just let them get on with it, and I try and add a good mix. It will still rot down, but like you - it can mean you run out of room at certain times.