Let's talk compost and weed seeds

[spinbaby]

I have a compost pile. It’s not a neatly constructed “hot” pile, but rather a rather random heap where I dump random weeds, leaves, and organic matter. It takes a while but it makes compost. Because it’s not a hot pile, I have a lot of weed seeds, making the compost useful only in the bottom of holes I’m about to plant something big in.

I read an article about sterilizing garden soil by covering it with clear plastic and letting the sun do its work, and I thought, why not compost? So I put a few inches of compost in a clear plastic storage bin, clamped the lid on, and set in on the driveway in the sun. The temperature in the bin gets up to about 130 F. After a few days, I’m going to dump the compost on a flower bed and wait to see if anything sprouts. Hopefully, nothing will.

[NRaleighLiberal]

1. That may not do it - I've used really hot water treatment on tomato seeds - also

microwaving (all part of studies to see what factors can enhance germination of old seeds) - and germination was fine. It would not surprise me if different types of seeds were killed at an array of temperatures.

Do report back on what you find!

[Drifter]

2. Stale Seed Bedding

You will need a weed burner, and a bit of room.

Spread out a layer of your compost (like a bed).
Water the hell out of it.
Cover it with plastic or landscape fabric (This will keep the moisture in and the light out).
Wait a week or two.
You are encouraging the weed seeds (in the top 2 inches) to germinate and begin to grow.
Uncover it and you should see a bunch of tiny weeds starting to grow.
Burn them with the weed burner.
You can repeat this after mixing the compost (to expose new seeds).

I use this technique on my beds as well as with compost.
There are definitely videos out there.

Cheers
Drifter

[spinbaby]

4. Like a flame thrower?

[Drifter]

5. Sort of ...

It is basically a propane torch in a form factor that makes burning weeds easy.

I have one like this:
https://www.drpower.com/productimages/image.axd/i.14997/w.515/h.515/small+weed+torch_r.jpg

In general it is safe, if you use common sense.

Cheers
Drifter

[Drifter]

6. This one is overboard

https://farmersfriendllc.com/products/weed-management

Cheers
Drifter

[Mr.Bill]

3. Years ago when I worked in the garden dept. of a large Super Drug store,

I was told the reason some potting soils were so much more expensive than others is they run it down a conveyor belt through a steam bath to kill weed seeds. Supersoil was a specific brand that did this, I think.

[spinbaby]

7. Up to 150 today

Sterilization depends on both heat and time. A couple more days and the compost will go under the marigolds and we’ll see if we grow weeds.

[WhiteTara]

8. Solarizing will kill your microbes too.

I have crab grass and I solarized 2 beds last winter. I should have done it earlier in the year, but I didn't and it really helped. I think that if I left it for a summer season, it would be perfect.

[spinbaby]

9. I can't do that

I’m not a vegetable gardener, I’m a flower gardener, so the beds contain perennials all the time. The container method does work, but turns out to be a lot of trouble for a tiny bit of sterilized compost.