Weed seeds in Compost

[James]

Hi Charles,

I have had an allotment for 4 years now and each year I learn more and more. It very heavy clay on the Wiltshire/ Gloucestershire border but over the years has had plenty of compost worked into it which is obviously good.

When I first took it over it was covered in weeds/ grasses and to save time these were just heaped up under the apple tree with plenty of soil mixed in. Last year I went to start using the pile which had turned into compost and was pleasantly surprised by how nice it looked. However when using the no dig method of spreading it over the soil I found that I got a huge number of weeds coming up. This was a nightmare in the salad/ carrots/ parsnips bed. I think that because of the amount of soil in the heap that the temperature never really got high enough to kill off all the weed seeds.

So I’m a bit stuck on what to do next. I still have a couple of cubic metres of it to use up and don’t want to spread it on the allotment surface and have the same number of weeds as before. I have considered digging a deep trench and putting it all at the bottom with the soil back on top but that just seems hard work and I would guess you have a better idea that may save a lot of digging?

I did build 2 very big compost bins today so hope/ expect to make compost with more heat in 2018 🙂

I should also say thanks for all your great youtube videos too. Very inspirational!

all the best,
James

[charles]

Hence it’s better to leave the soil alone… a shame you took off that soil.
I would spread it to get the fertility back, just grow potatoes and say squash through a mulch like cardboard. Keep two or three clean beds for carrots etc.
The weed seeds will be much less in 2019.

[James]

Thanks Charles. If only I’d come across no dig 4 years ago! 🙂 I have been putting a lot of well rotted cow manure on the beds in the last few years. With particular success on my Joan J Raspberries using no dig methodology. FYI the soil is excellent and had loads of organic material added over the last 70 years..

So I guess my plan should be as you say to mulch the beds for squash, courgettes, cucumbers, potatoes with the compost full of seed and then cardboard. and then for the beds with carrots salad, onions mulch with other stuff.

Just another question if you don’t mind. Would you mulch with the compost full of seed now and then cover in cardboard in the spring? Or do it all in the spring?

For the other beds I can get a huge tractor scoop full of well rotted cow manure for £10. It’s probably too coarse for carrots but am I right in thinking that it’ll be fine for anything I grow in modules and then plant on?

thanks a lot
James

[charles]

Great that you found no dig now at least!
I would leave laying cardboard until you see some weeds growing.
For the cow manure, best get it on soon so it can weather and be easier for planting.
Without seeing it, hard to say but it’s probably ok for all module plants.

[James]

Thanks Charles. I’ll get the manure on over the next couple of weeks. I’ve attached a picture of the load i got earlier this year. I’ll get it spread on and try to break it down to pieces smaller than golf balls as I’ve read elsewhere on your site.

James

[charles]

James that looks fantastic, what a great resource

[Author]

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