Hi, Bonnie:

One of the benefits of wintersowing is that damping-off is virtually unheard-of. That's something that occurs indoors. I don't recall anyone saying they had dampoff occur in wintersown containers. So, you don't need to worry about it. If you ever did start seeds indoors, I have read that putting crumbled sphagnum moss (not peat, this is the curly stuff. You can buy the curly stuff and crumble it yourself, or buy premilled stuff) I just try to sterilize my indoor growing medium and use a fan.

Now, for your wintersowing mix: last year, I mixed peat moss, perlite, and both dirt from my garden and bagged soil. For this year I have added dry horse manure. I had great success with most containers--the problem ones got just cheap walmart soil and perlite, because everything else was frozen. But if you want to just mix perlite and peat moss, you can. There will be no nutrients for the seedlings once they sprout, but you could use liquid fertilizer. I add the soil and manure to my mix in part for fertilizationit may take months to get everything planted out! I'm sure you can read up on what the Promix growers use to fertilize.

For just peat and perlite, to use right away, IÂd moisten the peat first by adding one or two drops of dishwashing liquid into a bucket, pouring water into it to mix the soap in without making suds, then pouring the water into a bucket of peat. I then try to push the peat down into the water, with a small bucket or pot lid weighted down. You should drain/squeeze the excess water off, and use it within a few days. If you want to make a lot at once, donÂt moisten the peat ahead of time, just moisten the mix using that method when itÂs time to use it.

Once the peat is moist, stir perlite into it, maybe 1 part perlite to 4 parts peat, or 1 part to 3 parts. If youÂve seen any commercial seed-starting mix, try to make it look like that. (When the peat is wet, thereÂs less dust from the perlite. You may want to wear a dust mask)

Now, fill a test container with your mix and check its drainage. Make sure you've made BIG holes for drainage. The best holes are on the sides, just above the bottom. I snip with a sharp pair of scissors, then jam the scissors in there and twist until it's at least ¼." When you dump a lot of water into the container, check that water is actually coming out of the holes. Tiny holes get clogged with stuff, or water tension prevents drainage.

If you want to add some soil or compost/composted manure, to stretch your budget or to fertilize, I'd mix light or medium soil with moist peat moss half-and-half. If the soil you have is heavy, use less of it. You could use even less soil, I just use as much as I can because itÂs free. Then add perlite and mix it in until it looks like commercial mix, and just add compost/manure to be maybe 1/10 of the whole.

I hope this info will help you, and if you have a question, just let me know!

I was thinking of mixing worm castings from my worm bin, vermniculite and sphagnum peat as a seed-starting soil. Would this work pretty good?

A mix I've been having good luck with is a 1:1:1 mix of sphagnum, perlite and a sandy potting soil sold as "Citrus Mix" (coarse sand would probably work as well). Sphagnum is fine when moistened, but is hard to get wet initially. You may want to shake up your seedling mix with a small amount of water in a plastic bag to get it evenly moistened before sowing seed.

Damping off usually is caused by using a nonsterile mix and watering too heavily. It doesn't just occur indoors either:

"We usually think of Damping Off disease as an indoor plant problem. But, it also occurs outdoors. We are less likely to recognize it outdoors as the loss of plants in the spring can be attributed to a number of things."

More info available here.

Bonnie:

I just noticed that you did say you're going to do some planting indoors, so I'm glad I mentioned the regular sphagnum moss, or sterilizing. Sorry that I didn't pick up on that, though. For your indoor starting, you could moisten the peat moss using boiling water (just be very careful!) and that should sterilize it. I do have trouble with pockets that stay dry despite stirring, meaning they're not sterilized. But, it's mostly sterile! (Aren't you glad I'm not a surgeon? :) ) Filling the indoor containers close to the top, and having a fan running in the room does a lot to prevent dampoff. Some people use a solution of hydrogen peroxide, or chamomile tea, as well. If you do a search, you should be able to find their formulas.

Eric, I just checked out that link. There's a lot of good advice on there for preventing damp-off, but they seem to suggest that we not fertilize seedlings at all. They do need fertilizer at some point. Also, instead of telling people not to grow in their basements, they should tell people how to reduce risk. I think a huge number of those who grow indoors do so in their basements, and to assume that all basements are dank mold factories is silly.

I think that I have had damp-off strike a tomato seedling or two after plant-out, but it really doesn't seem to hit our wintersowing containers. I believe that it's possible, (I dare not say it's INCONCEIVABLE, because we know what happens after we say that!) but no one has ever reported it. Some people who have never grown indoors wintersow, so maybe they wouldn't recognize dampoff. However, a lot of wintersowers have grown or still grow indoors, and would recognize the signs. This is just a guess, but perhaps our outdoor containers of soil are inoculated with so many organisms that things remain in better balance than when we grow indoors with mix we have sterilized. We may have a lot of stuff floating around in our homes (including whatever causes dampoff), but theres more stuff outdoors. Again, thats just my theory.

Stage rat, thanks for the helpful advice! I DO believe that I lost some sprouts due to damping off, but it was only in 2 or 3 containers, and I think I will try to plant seedlings out earlier this time to avoid it. Once I had everything in the ground, the remaining seedlings from the affected containers survived just fine. Maybe the containers needed to have more ventilation holes or something? Anyway, last year I just used a commercial potting soil, so it probably wasn't sterile. I will try using boiling water to wet the soil this time.

Thanks again for your help,
Bonnie

Bonnie: if your seedling stems sort of got skinny right at soil level and they fell over and died--most or all of them in a container--then it was probably damping off. And this happened to a wsow container? Good thing I didn't say inconceivable!

bencjedi, I found this info on using worm compost in your seed starting mix--it looks like you'll have to be careful not to let dampoff get started, but there are benefits to using the worm stuff:

from http://www.pioneerthinking.com/tv-seedstart.html

One of the most important factors when starting your seedlings is choosing your potting mix. It is often recommended to use a sterilized, soil-free starter mix to prevent diseases such as damping-off from taking hold of tender seedlings. I still recommend soil-less mixes to beginner gardeners but I, myself, have started to add compost and worm casts to my own mix. Here are a few reasons why:

First, soil-less mixes are totally free of any nutrients whatsoever. While young seedlings don't require fertilizers until they develop their first set of true leaves, I find having to feed them solely through a liquid feed quite cumbersome.

Organic fertilizers like compost and worm casts release their nutrients slowly and don't burn seedlings the way inorganic fertilizers may. Having these fertilizers already in the potting mix means I don't have to worry about feeding for at least 5-6 weeks. By then, I'm usually potting up the seedlings and adding fresh fertilizer anyway.

Second, I have found that growing seedlings with organic fertilizers in the mix tends to produce healthier seedlings.

The organic fertilizers help to mimic conditions in the garden where there is a multitude of fungi, bacteria and other soil organisms. Seedlings have to extract nutrients from the organic fertilizers just the way they would in garden soil. In contrast, I find that seedlings fed solely with liquid fertilizers tend to be less efficient at extracting nutrients since the liquid feeds provide them in a highly soluble form.

Third, the organic fertilizers help the soil mix hold moisture for longer periods of time. Most soil-less mixes are a combination of peat, perlite & vermiculite and drain very quickly. They require frequent watering, especially when seedlings grow their first set of true leaves and really begin to transpire. Both compost and worm casts retain moisture well and keep it available for growing roots.

Lastly, adding organic material into the potting mix helps to stretch the mix and make it go farther. This can be quite a cost savings, especially if your make your own compost or raise worms yourself.

One word of caution about adding organic fertilizers to your potting mix - remember that they will contain a wide variety of soil organisms and your soil mix will not longer be sterile. If you've had a problem with damping-off in the past, i.e. you tend to overwater your seedlings, you may want to only water your seedlings from the bottom or else stay with a sterile mix.

highalttransplant: Sphagnum peat moss and perlite equate to a peat-lite mix as popularized by Cornell Univ. Usually these are in a 1:1 ratio. Articles about mixing peat-lite and its application are available on the web, including one of the Cornell sites. Peat-lite mixes are available retail, too -- Jiffy Mix being an example. Usually dolomite lime is included to adjust the pH, since peat moss alone makes it naturally a bit acidic. An alternative to the Cornell peat-lite media are the UC mixes, which use sand instead of perlite. The UC mixes were developed in the 1950s, prior to Cornell's work. For commercial growers, peat-lite and its variants have the advantage that perlite is much lighter than sand. Don't mix garden soil into your propagation medium. You want the medium to be as sterile as possible, and garden soil introduces who-knows-what, and it has no real function for seed propagation. For propagation you don't need much in the way of nutrients, but some variants of peat-lite include organic compost. Once your plants are transplanted, you may want to think about some fertilizer. I'm using Osmocote 14-14-14 slow-release.

After talking with a few commercial growers, I've tried to use coconut fiber instead of peat whenever I can get it. My soilless mix is:
2 parts perlite
1 part coco fiber
1 part washed sand
1/25 part slow release pellet fertilizer (or dilute fish emulsion applications after germination)

I often use fast-draining cactus soil mix (instead of coco fiber) if I think the seedling will be in that container past the 4 true leaf stage.

The perlite I bought at Lowe's is Miracle-Gro brand- it contains low levels N-P-K (.04%, .01%, .06%). I'm planning to mix this 1:1 with sphagnum peat.

Interesting idea to sterilize the peat with boiling water- my 1978 edition 'Park's Success With Seeds' says to "drench the sowing medium with a solution of Benomyl fungicide (1/2 tablespoon per gallon of water) 2 hours before sowing seed."

I'm not sure if Benomyl is still available- does anyone know? I once worked in a commercial greenhouse operation where the "benches" were filled with a mixture of manure and topsoil, then covered with rubberized canvas and cooked with steam for a day, prior to planting their florist crops (carnations, mums, snapdragons).

Not exactly aromatherapy- if you can imagine.

The Cornell mix is 1:1 peat/perlite, but also adds limestone, bonemeal, and bloodmeal. Here's their large quantity recipe:
1/2 cu. yd. Sphagnum peat or coir
1/2 cu. yd perlite
10 lbs. bonemeal
5 lbs. ground limestone
5 lbs. bloodmeal

Whatever mix you use, if you're using peat, add a little limestone to reduce the acidity.

I do also personally like Pro-Mix, but Sunshine mix is good too. Pro Mix is 70-80% Peaat, 20-30% Pelite, a starter nutrient charge, Gypsum (calcium sulfate), dolomitic limestone, and a wetting agent (like coir). depending on which mix it is, the gypsum and starter nutrient may be half strength, and the perlite may be finer than normal, as is appropriate for a germination mix. Some of the pro-mix mixes also contain a fungicide. I find that the high quantity peat mixes are almost impossible to over wet enough to get damping off. I also use fans too, though.

If I were going to make my own, I'd go with peat, horticultural grade perlite, lime, and either an organic fertilizer (they release slow), or a mix of greensand, bloodmeal and rock phosphate. well, I'd want to stick to just that but based on my experimentation every year I'd probably also throw in some sand, leaf-gro and pine fines. I'm still searching for the perfect mix, but I generally do my germinating in Pro-mix type stuff.

I would still check at home building centers, such at Lowe's in your area. They likely have seed starting mix available. It will be much less hassle than trying to mix your own. The Peat Moss is also much coarser than the ready seed starting mix and contains larger matter that's hard to deal with when you use seed starting pots that are so small. Walmart and Meijers as grocery chains also carry seed starting mix. Meijers has weekly sales on and off for the mix at a better price than the regular $3.99 per bag. I believe the Meijers mix is made by a company called Hoffman and is very good.

I'm growing Calif. native salvias. Last summer I did a lot of online research on growing media (having known nothing previously), and I decided to mix my own peat-lite type of growing medium. Alas, I couldn't find things like dolomite lime locally, at least not in suitable quantities (HD had a tiny bag). I settled for EB Stone "Seed Starter Mix," which is a peat-lite type of mix, though it doesn't state the proportions of each component. This has worked well for seeds. I might have used Jiffy Mix if I'd found it earlier. For the potted seedlings I'm using Sunshine Mix #1, which is a peat-lite mix with a bit of fertilizer thrown in. It comes in 3.3 cu ft bales. I had at one point intended to use the seed-starter mix with a bit of compost or fertilizer for the potted seedlings, but it would have cost a fortune compared to the big bag of Sunshine Mix. So far, I'm happy with the results of both media that I'm using.