As Davidinct mentioned the standard ProMix has Mycorise included but you can also order it with Biofungicides for a little extra per bale ($1.45 from my supplier). Both of these additives have research support for reducing pathogen organisms and the biofungicide can even boost production due to the benefit of the root colinizing organisms. These are similar to a whole new line of commercial products like TC-22, Rootshield, etc. Either way this new technology in planting media makes good sense. The opposite, very risky alternative of using any unsterilized material can lead to a complete wipeout of your seedling crop in a few days from soilborn pathogens. I would never,ever attempt to start seeds in soil from the garden. Your time is too valuable to risk the crop loss.

Odd... I thought I already responded to this post, but I guess not. QUESTION: The soil less seed starter mix has no nutrients. The seedlings are growing their 2nd sets of true leaves...but how long can they stay in the soilless mix? Seedlings initially grow off what is contained in their seed leaves, and so have very minimal requirements from their environment except light, water, and something to hold onto (and initially, even the light requirement is more for hormonal issues than anything else). However, since yours are already to the point where they have two sets of true leaves, yes, they're going to need to be getting nutrients from their environment. Now, you can go about this two ways. One, you could transplant into a more nutrient-rich soil. Or two, you could keep them in the mix and just fertilize. The latter case is actually a simple form of hydroponics called static culture. :) And how long do they have to stay under the lights? I'm in Door County, WI. and will have 6 or more weeks to go before no frost danger. They need to stay under the lights until they go outside. Sorry! And I'm not sure if it's SIZE or WEATHER that will tell me when to move them out. Will the plants even survive if they stay in soil-less, under florescent lights that long? Weather. Don't put your plants outside in weather that they can't handle, and be sure to harden them off first! And yes, plants can grow under lights indefinitely... assuming you give them sufficient space and light! **What do any of you experienced people think of this idea:Instead of just soil less starter to begin...Mix 3/4 sterilized potting soil and 1/4 soil less starting mix. Moisten and use this combination to start seeds? I start my seeds without soilless mix at all. I make a soil out of a mixture of peat and compost, with a small amount of time-release fertilizer, and optionally, depending on the needs of the particular plant, sand, perlite, or vermiculite. A base of peat plus compost is great at retaining nutrients, does pretty well with retaining moisture, and is pretty airy. I'm very pleased with the results I get out of it. The only time I transplant before putting things outside is when I have too many seedlings in a pot.

Mixes like Fafard #2 (vermiculite, perlite, and peat moss) are used by lots of professionals because it gives the seeds the right conditions for germination. This mix really doesn't have any nutrition to speak of, but the seeds themselves provide nutrition to the plant for awhile. So, seed starting mixes aren't really soil, but they are good for starting seed. You get a high percentage of germination. You have to transplant the plant to real soil within a month or two, or it will get sick from lack of nutients. "Potting soil" really isn't soil from a soil science perspective, though it may have some nutrition. Soil is the mineral stuff in the earth's horizon. I used to be skeptical about seed starting mix, but I'm sold on Fafard. I buy just one bag a year, because it goes a long way.

I'm sorry jtcm but it wasn't my intent to offer that link as some sort of definitive authority, just a source of additional info on the question. There are multiple other sources available online that you can Google if interested. I just thought you were looking for general info. While we're at it...let's re-use our trays without cleaning them and keep the seedlings covered until the true leaves emerge. I don't see how that follows. There is a great deal of difference between adding small amounts of well-cooked compost to a mix and intentionally using dirty trays/containers or keeping seedlings covered. As I said above, I'm far from the only person who uses compost in their seed starting mix. A search here will pull up many discussions about it. And if you believe your seed starting mix is actually "sterile", in the usual sense of the word, then you are misled. Most all packaged seed starting mixes, including ProMix and Metro Mix not to mention all the Scotts products add composted ingredients in various forms to their mix. All the organic seed germination mixes on the market include compost in some form. ProMix even advertises the addition of mycorrhizal fungi to their mix as one of their selling points. And then those bags get transported all packed together inside a hot truck to the Home Depot or Lowe's or Walmart outside store yard to lay around in the sun and the rain until someone buys them. Meanwhile the composting process started in the factory by mixing those ingredients goes on in the bag. Feel free to do some additional research on the issue yourself if interested or, if you prefer, just don't use it. The seeds will germinate either way. ;) Dave