Plain compost for seed starting?
 

Read about starting seedlings in compost in an old organic gardening book. How bad an idea do you think this is? Has anyone ever tried it?

I did try with seeds for plants that I am not really relying on, and there were no noticeable problems. Had good germination and no early loss. Now they have been potted up and are doing fine so far. Just wondering if this is just a lucky coincidence.

That is good to know because I am out of potting mix. If it worked, keep doing it. Keep using it for your non precious seeds and report. Your experience is a good lesson. :)

I tried cow manure and it didn't work. I have some dry barn lot "soil" and planted too many verbascum seeds. I transplanted some into this cow manure and they damped off. So now I know.

Still don't know if I can mix it with other stuff in pots and use bigger plants. I hate to spend all the money I spend on potting mix when I have a huge pile of cow manure and rotted wood that looks like peat moss.

I would think that most compost may be a little hot for tender seeds and seedlings. An eye will be kept on the results.

I don't use my compost to start tomatoes or peppers because usually other seeds will sprout first (volunteer tomatoes are the ones I'm most concerned about). I used it one year (with wintersowing, so everything sprouted slowly) and ended up with a couple volunteer tomato plants, rather than the varieties I wanted.

But I do use my finely screened compost for starting brassicas. Kale and broccoli seeds are vigorous, and even if I have similar ones in the compost, they're likely to turn into good plants.

I also use my compost for potting up tomatoes. By the time they're a few inches high, they'll outgrow any volunteers in the compost. I grew a couple hundred tomato seedlings last year and didn't lose any to damping off. Snails and slugs got a few, though.

If the compost is finished, it won't be hot.

One other caveat about using compost. When I've added it to indoor plants, I've gotten fungus gnats or whiteflies indoors. So if I were growing my seedlings indoors, I wouldn't use compost.

I've use well composted manure from our animals to start seeds but the only thing different I did was put store bought seed starter on the top of the manure.All the hot peppers and tomatoes did very well this way.
Gene

Thanks Gene. That is a good idea.

The reason I prefer a sterile mix is the issue of bugs. My compost pile is more of a cooler pile, not alway hot. Bugs will lay eggs and they will hatch. I agree if you don't plant your precious seed it should be fine. I lost a lot rare seed just by having compost in the room, had other rookie issues but my room was full of all different kinds of insects due to overwintering of peppers I had just spread compost on and kept them in the same room.

There is no way to know what the nutrient balance is in your compost. I know that it would be a bad idea for me because I threw some dried beans in mine and they came up yellow from nitrogen starvation.

[quote=maricybele;158684]The reason I prefer a sterile mix is the issue of bugs. My compost pile is more of a cooler pile, not alway hot. Bugs will lay eggs and they will hatch. I agree if you don't plant your precious seed it should be fine. I lost a lot rare seed just by having compost in the room, had other rookie issues but my room was full of all different kinds of insects due to overwintering of peppers I had just spread compost on and kept them in the same room.[/quote]

Throwing some fresh manure or even nitrates on the pile should help it to heat up from the inside out. I cannot turn my pile like I need to, so I broke all of my own rules before the rain and put a fairly large amount of nitrate on my pile the other day due to all the extreme cold and wet conditions. Without the heat inside the compost won't kill all of the bad things that can develop in an anaerobic pile. With each passing month it is harder for me to even fork new materials into the pile, much less turn it!

[quote=TZ-OH6;158696]There is no way to know what the nutrient balance is in your compost.quote]

This can be tested in a soil lab.

Yes, of course it can be, I should have chosen my words more carefully and put in "without testing". I suspect testing would cost about the same as a bag of seedling mix.

Thanks for all the input. I must not have had live seeds in my compost, but I can see the potential for a problem there! Potting up in compost should be a real potential benefit, particularly if I continue to give away 100+ plants each year. Looks like I will expand my experiment some next year, but I will still start many in seed starting mix until I have more experience with this.

[quote=matilda'skid;158636]

Still don't know if I can mix it with other stuff in pots and use bigger plants. I hate to spend all the money I spend on potting mix when I have a huge pile of cow manure and rotted wood that looks like peat moss.[/quote]

I used a mix of sedge peat (cheap "black stuff in a bag", as I call it), pine bark, and thermal compost in some 24" pots with no problems.

Most of what I have experienced is covered here regarding nitrogen availability, fungus gnats, and weed seeds. I have used 3+ year old leaf compost for potting up seedlings in 2.5" pots with great results, only to be followed up with 100% failure when I used some 1 year old leaf compost that looked like peat moss.:panic: The 128 cell trays I use for seeds are such a low volume, it is worth it to use a peat/coir-perlite mix. Even with this mix a few fungus gnats usually appear. Amazing little things.