Is it really that big of a deal? JMO but yes, it is. Once you experience the loss of multiple seedlings from damp- off or find your seedlings infested with gnats or spider mites from the potting soil you'll quickly return to the soil-less mixes. ;)

That said, homemade compost as an additive is great or bulk peat is inexpensive and can be used to extend your on-hand mix or you will find numerous discussions on the Container Gardening and the Growing from Seed forums on how to mix your own soil-less mix.

Good luck with your seedlings. ;)

Dave

thear

Instead of mixing it, why don't you put the potting soil on the bottom and add the seed starting mix on top of it. That way, the seeds can take advantage of the fine texture to germinate (baby roots and leaves) and yet the roots can do fine in the potting mixture below once they're up and growing.

do not use potting soil to mix with your soil-less mixture , you will have damp-off .if you can not get to to a store to get more soil-less mix ,you can sterilize some of your garden soil ,not potting soil. take a small amount of soil from your garden and spread it on a cookie sheet about a inch thick put it in your oven at 160 degrees for 45 mins. this mite smell a litte but the soil will be safe to use for seeds.I hope this will help you cactus Pat.

Thanks for the timely replies....
After two "damp off" warnings I've decided just to take my cheap arse up to the store and get more seed starting mix. One of these years I will be able to grow tomatoes for zero dollars :)

Troy

Troy!

Don't bet on it... :-)

Ok... we're warning against damping-off but recommending compost to sow in????

Since I'm the one that mentioned using the compost, I assume this question is directed at me? Does adding compost cause damp-off?

No, it's the battle of the fungi! ;)

Many who post here talk about adding some homemade compost to their seed starting mix and even topping the containers with some composted shredded bark so hopefully they will chime in too. In my experience with trying it, it has caused no damp-off problems. Some claim it even goes so far as to prevent it because the mycorrhizal fungi kills off the Rhizoctonia fungi that causes damp-off.

That said, "compost" means different things to different people. ;) Mine is all organic materials (no dirt/soil), just shredded leaves, shredded hay, kitchen scraps, and composted cow manure, that has all cooked well and contains high levels of mycorrhizal fungi - so much so that you can almost see it growing.

Article linked below for more info.

Hope this clarifies my comment above.

Dave

Here is a link that might be useful: Damp Off - Trouble in the Seed Tray

Damp off is fostered by stagnant air, make sure your containers have adequate ventilation if you're starting seeds inside.

OK Anney, now it's a challenge!!! LOL!!
I'll post in a couple years when I've grown my first "zero dollar" tomato....
(wow, now i have to build CRM cages, and start a compost pile, and figure out how to shred tree bark, and umm.... what else.... lol)

LOL...well, if THAT website says so, it HAS to be true.

Ok, it's starting to make sense now. Lets add compost to a sterile seed starting mix. 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'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

All 500+ of my tomato seedlings were started in 100% home grown compost. Out of that I have had 2 seedlings that looked like they had dampening off. All of my seedlings are now between 3 and 4 weeks old. I had more problems with dampening off before I started using compost than I do now. Poor air circulation and constantly wet causes the majority of dampening off in my opinion.

Patrick - Shreveport, La.

I've only started from seed once and it was last year and I used Jiffy pellets with great results. Will use them again this year. jmo.

I was going to try soil-less Pro Mix but the damp-off scares me and the planting instructions from my supplier says to use 'Damp-Off' on the soil before laying the seeds.

The pellets worked for me, so if it isn't broke ..... :)

I would trust Dave's advice. He's been at it forever!

Rory

Fungi causes damping-off. Without that, you will have no DO. I don't care how wet or stagnant the conditions of the tray are. So if you want to add compost(which there is absolutely no point to) or something other than a soil-less mix that is completely laden with all sorts of fungi and other organisms....be my guest. All it will do is increase the chances of setting your season back a few weeks.....and maybe save you a buck or two.

Be careful whose "opinions" you "trust" on the internet. ;)