[shokkyy]

Last autumn I spread loads of garden compost over my veggie plots and flower bed. It was well rotted down and looked nice, but everywhere I put it I'm now seeing zillions of tiny little weeds sprouting up. I know it's from the compost cos the veggie plots are raised beds with soil that was imported in new last year, and they went through the whole of last summer with barely any weeds at all.

How the heck do you make compost without introducing zillions of weed seeds everywhere you put it?

[savbo]

ultimately you can't stop it...but by avoiding putting ripe seed in  and by making sure you let it got hot, you can reduce the amount.... another trick is to use it at the bottom of trenches etc where the light doesn't get to it -  that's what I was recommended to do with our site compost which isn't as well vetted as my own pile!

M

[Salmo]

What to do now?

Cultivate the surface as soon as it dries a little to kill the weeds before they get large. This will also stimulate more seeds to germinate. Keep hoeing.

An alternative is to spray with glyphosate a week before you want to start working the soil. After a week you can cultivate and sow. The weeds will carry on dying. It will work even at low temperatures, it just takes a little longer.

[solway cropper]

Just shows that you have to be a bit careful about what you put on the heap. Like everything else in gardening it's a steep learning curve. Any weeds I pull that show seed development go in the green recycle bin or sometimes I put them in a black bag and leave them out during hot weather. They usually heat up enough to kill the seeds but as a precaution the resulting fermenting mess gets tipped on the big heap and left for a couple of years.

[shokkyy]

Just shows that you have to be a bit careful about what you put on the heap. Like everything else in gardening it's a steep learning curve. Any weeds I pull that show seed development go in the green recycle bin or sometimes I put them in a black bag and leave them out during hot weather. They usually heat up enough to kill the seeds but as a precaution the resulting fermenting mess gets tipped on the big heap and left for a couple of years.

But that compost heap was about 10 years old

[Yorkie]

Yeah, but they've seen the light for the first time 

[Salmo]

I would bet that weeds have grown on the heap and seeded, hence your problem. This can happen with manure heaps too.

[Ivor Backache]

Last autumn I spread loads of garden compost over my veggie plots and flower bed. It was well rotted down and looked nice, but everywhere I put it I'm now seeing zillions of tiny little weeds sprouting up. I know it's from the compost cos the veggie plots are raised beds with soil that was imported in new last year, and they went through the whole of last summer with barely any weeds at all.

How the heck do you make compost without introducing zillions of weed seeds everywhere you put it?

You haven't told us how you made the compost. Compost heaps need to be a minimum of a cubit metre to generate enough heat to kill the seeds. It may look like the real thing, but you must have the heat, and to get that you need to compost  carbon and nitrogen at the rato of 30:1.

[shokkyy]

You haven't told us how you made the compost. Compost heaps need to be a minimum of a cubit metre to generate enough heat to kill the seeds. It may look like the real thing, but you must have the heat, and to get that you need to compost  carbon and nitrogen at the rato of 30:1.

It was certainly way over one cubit metre, enormous great heap, but I'm afraid there was nothing scientific about its construction. It was just the normal heap of assorted kitchen waste, grass mowings, old plants and weedings from a very big garden, accumulated over a very long time. Now we've about got rid of that old heap I've started a row of compost bins (filled 6 so far), so the new compost made will no longer be an open heap at least.

[JayG]

Ivor is very lucky if he can consistently create compost heaps which heat up enough to kill weed seeds.

Most people's heaps are like shokkyy's; one or more piles or bins of stuff in various stages of decomposition which are added to as and when material becomes available, so rarely heat up much if at all.

I think it makes sense to avoid composting material known to be very "seedy", I also keep telling myself that hoeing is a very enjoyable and therapeutic activity! 

[strangerachael]

the seeds that germinate from compost are nearly all annuals, so look on the bright side - this stuff will supply you with plenty of material for next year's compost! I let my 'fat hen' get quite big, and as long as you pull it up before it goes to seed it provides lots of bulky, sappy green stuff, mixed with something carbon rich like straw or paper it gets really hot really quickly and composts down in no time. Lovely!

[shokkyy]

Ivor is very lucky if he can consistently create compost heaps which heat up enough to kill weed seeds.

Most people's heaps are like shokkyy's; one or more piles or bins of stuff in various stages of decomposition which are added to as and when material becomes available, so rarely heat up much if at all.

I think it makes sense to avoid composting material known to be very "seedy", I also keep telling myself that hoeing is a very enjoyable and therapeutic activity! 

Yeah, trouble is you rarely get the chance to hoe when the ground is dry enough for it to do anything very useful. Or maybe it just seems that way. Between last summer and this winter and the prior winter I can't remember the last time we had nice weather

[shokkyy]

the seeds that germinate from compost are nearly all annuals, so look on the bright side - this stuff will supply you with plenty of material for next year's compost! I let my 'fat hen' get quite big, and as long as you pull it up before it goes to seed it provides lots of bulky, sappy green stuff, mixed with something carbon rich like straw or paper it gets really hot really quickly and composts down in no time. Lovely!

What's a fat hen?

[DD.]

What's a fat hen?

Not "a" Fat Hen, just Fat Hen.

http://www.gardenorganic.org.uk/organicweeds/weed_information/weed.php?id=17

[Hoodsie]

What a good site that is very informative!!

I have added that to my favourites as i think i will be needing it in the future

thanks