Does anyone here sterilize their container soil?
My container mix for growing things is a combo of vermiculite, sifted peat moss and homemade compost. I started seeds in this and have had decent results, but I've lost some seedlings too, that grow up a bit and then keel over. I suspect maybe it's the fungus that causes damping off, or maybe some other bad bacteria/microbes/whatnot in the soil.
I just acquired an old microwave today and I thought I'd set it on my patio table and sterilize my mix as I use it. Good idea? Any warnings or tips?
I grow most everything in containers and I've always heard to sterilize used container soil, just never actually did it! I'd be interested in what people think about it. I will have about 30 containers.
Thanks!
soil sterilization
I grow everything in pots. I'm using some of my original soil that was purchased in 2005 from Lowes and Walmart. It's the cheap stuff, potting soil, composted cow manure or pine bark fines, either straight or in combination. I reuse it year round but try to rotate the crops. I haven't had any problems with it. I always empty one pot into another or several so it gets mixed. Usually it has earth worms in it but haven't seen any lately. I think the combination of unusual cold and wet conditions wiped them out. I add homemade compost and avoid pesticides. I do use some commercial fertilizer.
I think microwaving would be too big a job. The only problems I've had with damping off is with seedlings in the house. I use that same potting soil to start seeds and saturate it with peroxide water. It has an antiseptic effect and carries oxygen to the roots. It's harmless so the recipe isn't critical. I use 1/4 cup more or less to a gallon of water. That puts an end to damping off.
I've sanitized by thoroughly dampening the mix in a big pot, covering with lid or alum foil, then into the oven at 200 for a couple hours. Simpler than using mwave.
I do pretty much what twiggy does. I don't think your soil mix is the problem as peat and vermiculite are sterile for the most part and you know what is in your compost. One issue may be if your compost is not completely broken down - ok for established plants but not so good for seedlings.
What I do to prevent damping off is either peroxide water or sprinkle the top of the soil you are going to plant in with cinnamon and mix it in a bit. It is also a natural antiseptic and a lot of people swear by it. Also try not to top water when seedlings are small.
Interesting about the cinnamon, locakelly. Thanks for that tip! As for knowing what's in my compost -- well, it's got leaves, grass, old veggies, coffee grounds and a few shovels of ordinary dirt. I know what's in it -- but no telling what critters or fungus might have come along for the ride, right? I did sift my compost so no big chunks, although there are still chunks in the bin. I have been assuming that if it is small enough to get through the holes of a strainer, it is broken down, but maybe that is not strictly true.
tarheel2az, I don't want to use my oven. I tried it once years ago and it stunk up the place. Hubby curls his lip at most of my gardening exploits now...
twiggybuds, it was seedlings I started in the house that suffered the keel-over. Just a few, but I watered them all the same, so the damping off thing was what I suspected (but what do I know? I'm new at this). I did use peroxide water but not until I'd already lost those few. (I didn't lose a lot, but maybe 15%). I'll do better next time. I don't think microwaving would be too big a deal but you might be right. Rather than do it for all the containers, maybe I'll just concentrate on the mix for starting more seedlings. That won't take much effort.
Speaking of worms, I'm finding some this year! Last year I found only 1 worm in the yard, but after digging, planting and composting a couple beds last fall, this year already I have found 12.
I first heard about the cinnamon from LazLo and after trying it I have to say I have noticed a definite decline in the number of casualties - lol.
LiseP - I saw a thread somewhere on sterilizing soil mix, but with the search feature down I can't search for it. I want to say it was in the seed germination forum but I could be wrong.
Molamola - I hear you on the growing bog plants - lol. Living in the desert I just assume everything needs a lot of water and that is very far from the truth...