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organic seed starting?

In the past, I've always started seeds with pre-bagged seed starting mix. When I stopped to think about it though, I began to wonder if some of these contain chemical fertilizers or even fungicides.... :?

Besides, I want to be self-sufficient. :D I've always understood that seeds should be started in sterilized fine tilth soil.... So, does anyone have a good home-made seed starting recipe? I have compost, I have leaf mold, I have sieves/riddles, and I have sand.... :mrgreen:

Also, I don't have hot compost, but could I sterilize small amounts of the soil just enough to kill the weed seeds, fungi, and diseases, but not enough to destroy all the beneficial bioactivity :?:

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I hope that you get a reply to this. Last year when I was at a local gardening store they thought that I was crazy for not wanting to start my seeds in the regular starting mixes. I wanted an organic starting mix, which they did not have. I ended up buying organic potting soil and sphagnum moss...they said that was not a good enough starter...

Although the seedlings did very well I too would prefer to make my own mix. I also found the cow manure pots that I purchased did a good job, but I am not sure if they were from an organic source - organically fed cows....anyhow I do hope that someone on the forum has a good homemade seed starting recipe! I am interested as well!

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Sorry for dredging up and old topic, but does anyone have any good tips for organic seed starting? Is there a decent organic starter out there?



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Well aged, composted and heat treated lawn clippings (12 months old or older would be good). Pulverise with shredder (flail) and mix with 50% perlite.

Moisten mix and store in clear plastic bags (20 litres plus) for a month or so - to allow moisture to penetrate organic matter.

Use as needed.

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I don't have an answer. I'm basically an organic gardener, but I gave up on it for my seed starting. When I was trying, I brought in some compost and baked it, which smells really nasty and kills everything (including beneficials). The compost is really heavy, so you need to lighten it with perlite, vermiculite, etc. Even so, I tried different mixtures of compost, perlite, peat moss etc. My seedlings just didn't grow nearly as well as they do in commercial potting soil with Miracle Grow. So I use that to start them and then grow them organically once they are outdoors in the ground. It's my compromise, but if others are doing well organically, I'd still be glad to learn...

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Well, I didn't get any replies back then, so I just went ahead with whatever I had.

FWIW, here's my seed starting mix recipe: What I've been using is my own unsterilized compost sifted with a double layer nursery flat basket (1/2"~1"), play sand out of the kids' sandpit (it's surrounded with cut up tree stumps. They decay over time and are replaced. I get the sand mixed with crumbled decayed wood), and my Good Under The Wood Pile Dirt (I've explained this at length elsewhere). I sift with 3/8" riddle and mix them all together. I've used this mix for flats, soil blocks, and paper pots. For up potting transplants, I add to the mix soaked/swelled/crumbled alfalfa pellets for extra N as well as a dolomite lime, greensand, and rockphosphate.

So far, everything has been growing well. I think the high level of biological and mycorrhizal activity is actually helping. No mold, no damping off. I do get a lot of weeds, which I pluck out with tweezers when I inspect/water the seedlings. I'm also getting a whole bunch of critters -- earthworms, millipedes, centipedes, nematodes, pillbugs, spiders, some kind of gnats. So far, there hasn't been any noticeable damage. I remove pillbugs and millipedes because they creep me out, but I've left the centipedes to patrol the seed flats and earthworms to tunnel around and cast. 8) I just removed a fat nematode out of the tomato flat because I wasn't sure if it was friend or foe, but I generally leave the thread-thin newborns alone. :mrgreen:

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1 part homemade compost, sifted through 1/4 inch screen for big stuff
1 part perlite
1 part sand
optional* add a mycorrhizal inoculate

you can use wormcompost in place of the compost with great results, but its best if its your own vermicompost.

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you don't need to buy "seed starter potting mix", most of these contain a lot of peat, which can be harmful to seedlings at a high percentage. a standard potting mix, as long as its organic, fine textured and rich in nutrients will work great. I would advise against using sand and perlite should be added after the germination stage.
Last edited by ChefRob on Wed Sep 02, 2009 11:13 am, edited 1 time in total.

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On another thread we were talking about coconut coir and I read that it is a great seed starter. They said that it does not have nutrients of it own but that you can soak it in water mixed with what you want to feed your plants and that it stays moist and slowly feeds your plants. For next spring I am using coconut coir soaked in compost tea or kelp tea and see how it goes.

We were also looking for places that sell it and I suggested the pet store where they sell reptiles, but someone on another thread suggested a store for dr. earth and they sell coconut coir at that store. I don't know how good it is but it may be worth a try. Also I found that if you search coco coir stores come up too.

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