I'm confused - why would you? The bulk ingredient in potting soil (basically all commercial brands are soilless these days) is usually peat, or ground bark. Emphasis is on formulation for aeration and drainage for use in an enclosed space (container). What did you use in yours if the areation quality seems missing now?

If you purchased a commerical brand..was it potting mix or potting soil or garden soil? Most wintersowers use potting mix, which is a lighter type of seed starting mix.

I have tried Miracle Grow, Espoma Organic potting mix and Fafard, and recently tried Hoffman's..I really liked the feel of the Fafard. Hate Miracle grow but that seems to be the one that most big box stores like Home Depot, and Lowe's sell. Miracle Grow seems full of junk to me, and heavy. I added perlite to it upon a veteran gardener's suggestion. The other day I drove a far distance to get more of the Fafard and when I got there in the Fall. I couldn't find the same bag and a supervisor was directing several employees that were stacking fertilizer or some other product on a pallet and asked if he could help me. I asked for what I had purchased before and it seems that garden center/nursery has stopped selling it because they started getting a lot of complains from gardeners. I just wonder if these manufacturers offer store owners big bonus bucks for pushing certain products? I worked in the food service industry for about 13 mo. years ago and manufacturers would offer food distributors big bonus money(we called it spiffs)for pushing their product. I have a feeling the same practice happens in the Garden center/nursery industry. I told him I had planned to sow flower seeds using 4 in. nursery pots outdoors..There were 2 or 3 varieties of Fafard there, but none of what I had bought before. He suggested Hoffman's which I had heard cons about. I took his advice but when I got home, I started thinking that maybe I hadn't explained myself well enough. Maybe he thought I was using the 4 in. pot indoors "under the lights ".

My suggestion to any wintersower, and I hope I will take my own advice the next time is to keep the empty bag or front of the bag of the product you find feels right to you. I had called ahead and spoke to a lady, explained what I was looking for, and she called that dept. and came back on the phone and said that they had the product I was looking for.
With the cost of gasoline these days, I think twice about driving a far distance to get a certain product when I might could use a similar product that is sold nearby.

Seems silly to save an empty bag of a product you used before and liked but maybe it will help you explain exactly the product you are looking for. If you don't want to save the entire bag, cut at least the front panel off. You can wash the soil that is left behind on the bag off, let it dry and it can be slipped inside a ziploc bag to take to the nursery/garden center if needed to show the employee exactly what you want.

I have never heard of any potting mix having clay added but I've only been sowing flowerseeds for 3 yrs. so I know I still have a lot to learn.

Hoping everything turns out okay for you. I hope my suggestion helps.

Not silly at all. I do it all the time. I have a box of plastic bags of stuff I've used. Now I take photos of the labels too. (Also the plastic bags eventually come in handy when I'm weeding.)

Question, when you use miracle gro and give it a good drink as suggested, how often you will have to water. or you basically look at the container and if the soil doesn't seem to dry don't water, water only when it looks dry. correct? Hopefully the condensation, evaporation cycle should retain the water in the container for long time, is this correct?

OK I'm rambling. That's what a long day and half of a drink will do to a girl. Moral of the story--soilless potting mix with the lightest texture you can find, and you should have great luck with germination.

Martha

Those are some powerful insight and darn good observations. I learn something new everyday.