Is it the compost????

I last year when preparing the veg patch for the first time mixed in some compost. This year i have lots of weeds that are of very similar description. But thankfully no reall suckers like dandelions!

Is it because weed seeds can get in the compost from mowings and even vegetables??

also, i have been putting spent compost from growing seedlings in the compost bin. There is a chnace that there are still seeds thsat havent yet germinated in the compost. Is it likely these will poop up next year?

thankyou

 

Hi VAFM. It depends how well your compost heap is working. In theory it should get so hot that it kills any seeds but maintaining a 'good' compost heap is an art in itself. You'll find plenty of advice on the internet about what to put in your compost and everyone seems to have their own way of doing it. I've been trying for years to get a good garden compost and not managed it yet :(

 

I agree with Terrier. In practice, the outer sides of a heap never get as hot as the core. And if you turn the compost regularly, heat is lost for a while. Which means you're likely to get some seeds surviving. I've currently got unidentified members of the cucurbit family and a few tomatoes merrily sprouting in my borders where I spread last year's compost. They're easy to deal with but it's not advisable to try and compost any tough or invasive species.

 

I still have not mastered composting but every year the process is getting faster as I make changes to how I do things.

But I dont attempt to compost weeds at all, they go into the council green bin, I figure their compost heap is bigger than mine, so will heat more and kill weeds that way.

As I understand it now, heaps need to be relatively airtight so they heat up, and turned to put air into it which helps the composting, but does lose heat as Flirty mentions.

Steve...

 

Two methods of making compost the hot and the cold method,the hot one you need at least 1cu mtr of material (store it in bags until you have enough to put together)put it in a ventilated container all at once, the material will heat up which speeds up the rotting process,it will not generally get hot enough to kill perennial weed seeds so don't put them on you will end up just spreading them around the garden,heaps usually only reach 30c this just speeds up the rotting process,you need 60c to reach pasteurising temperature and not many heaps will reach that no matter how well they are made (some seeds will even even survive this) under this temperature it's not enough to kill any diseased content so don't put this on either,turn the heap regularly to enable the outer layers to rot down,this method is the quicker of the two in producing compost.The second method is the cool method, [align=left]cool composting takes a little longer to produce results and is ideal for the small scale gardener using a compost bin. You make the mix in the same way, with layers, a good green/brown mix, moisture and air, but you can add the layers slowly as material becomes available.[/align]
[align=left]The material will still heat up, but usually to about 30 celcius or so it still isn't hot enough to kill off as many weed seeds or diseased plants, so be careful of what you put into it.[/align]
[align=left]One advantage of cool composting is that the lower temperatures mean more worms can survive in the material, which in turn means you will get a finer end product. It might take six months to a year to get good results this way.This is the method I prefer as I don't have sufficient quantities of material to do the hot method or the room because you really need 3 bins on the go one in use, one "cooking",and one in the making.
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My answer to the weed problem is to sieve it through a 10mm sieve, bag it, let the compost sit for 3-4 weeks in a warm place (greenhouse) to germinate any seeds then run it through a sieve again before using it. You'll kill off 90% of the weeds without destroying any of the 'essentials' in the compost. This is the preffered method for use with pots and seed trays.

For spreading rougher stuff on the garden it just gets dug through and weeded in the usual way. Even potato peelings will sprout!

I've also found that bought, supposedly top quality, compost will still have weeds in it, really they are just a fact of life