Sterilisation of compost?

[Rich66]

What is the best method for sterilising compost?

[Tony R]

Hi Rich,
You may get many diverse answers to this question from C&S enthusiasts, so there may not be a 'best' way, but may include: using steam, or microwave, or oven, or boiling water, or do nothing. Depending upon what I'm using the compost for, I currently adopt the latter two. I've been banned from using the microwave or oven!
But here is a layman's guide, that is worth a read: https://theyardandgarden.com/how-to-sterilize-soil/

[Tina]

wet compost in your pot/tray in a zip top bag microwave for 8-10 mins

[Rich66]

I’m going to be sowing a load of seeds next weekend and I just wondered how important it is to have sterilised compost for this. Is it crucial for this or if I don’t can it cause issues ?

[habanerocat]

You'll get different opinions. I have two threads on here bookmarked and there's also a society seed raising leaflet.

viewtopic.php?t=166614&hilit=a+busy+day

viewtopic.php?t=171130&hilit=Seed+plant ... as+started

https://www.society.bcss.org.uk/images/ ... atemix.pdf

[cactusK]

We sterilise compost in the microwave for sowing seeds. A couple of years ago we had a big problem with fungus gnat larva hatching in the compost so that's why we sterilise it now. We never really have a problem with fungus, mould, etc.

[Davey246]

Damp compost, microwaved until it is steaming, timimg of which will depend on how moist whatever quantity of compost you are heating.

Ordinary polythene gets very soft, stretchy and delicate at 100+C. Far safer to use roasting bags, which will last for ever - I have only ever bought one box and they are still in use after many 10kg compost having gone through them. For extra safety, especially as the microwave wll near certainly be the one in the kitchen, use one bag inside another as you will get tiny holes at some stage. Loosely close them (mine came with oven-proof re-usable plastic ties) - maybe something like a pencil can still be pushed through the closed neck. They will plump-up nicely when the steam gets going.

I usually gently rumble the contenets half way through the cooking.

For large quantities, I have used a baby Belling stand-alone laundry boiler (do they still exist?).

I’m going to be sowing a load of seeds next weekend and I just wondered how important it is to have sterilised compost for this. Is it crucial for this or if I don’t can it cause issues ?

Not essential, but a huge benefit.
If it is done properly, you will get nothing but C&S seedlings. Commercial composts have been sterilised, in the main, but the bags aren't sealed so will normally contain algae and moss/lichen to a greater or lesser degree.

[Tina]

I have a cheapie microwave in the greenhouse under the bench, its ideal in the hot greenhouse for warming the shelf above

[eduart2]

I've been banned from using the microwave or oven!

Me too! Some fifteen or sixteen years ago my wife came home quite unexpectedly (few hours earlier than planned)... and that was the end for my dirt cooking!

However, I stopped trying to sterilize the soil some years ago. It depends also on the plants you are growing.

[el48tel]

I've been banned from using the microwave or oven!

Me too! Some fifteen or sixteen years ago my wife came home quite unexpectedly (few hours earlier than planned)... and that was the end for my dirt cooking!

However, I stopped trying to sterilize the soil some years ago. It depends also on the plants you are growing.

No Microwave ... banned from kitchen .... told that good bugs are killed as well as bad bugs .... so I don't bother either