I have never baked or done anything to sterilize my potting soil before using it for my own purposes, and I have never had any real problems. I think for the most part it is sterile when you get it. In college I remember using steam to sterilize soil that we were reusing in the greenhouse rose beds...but that was because it was used:) I know that a lot of people do use special seed starting soil mix, but I always just use Pro-Mix potting soil. I;m sure some folks will tell you to use seed starting mix, and others will say it doesn't really matter (like me!), but what it comes down to is what you personally prefer. Why not try a little experiment and start some in the finer mix and others in regular mix...and see if it makes a difference to you! I just find it easier to use one kind, and I buy the huge 3.8cu ft bails.

Looks like the prills of slow release fertilizer, commonly added to container grown stock or planting medium.

Thank you Nc-crn and Jean001 for the posts. Many container gardeners have many different experiences for their growing medium. They think the one they use is the best or better than the others. In our forum also so many people have so many different opinions of the growing medium. I cannot say which one is the best. For my growing medium DE cat litter is better than the perlite. So I stopped using perlite. DE cat litter is one of the best for the roots for me. I use it for mulch and all my containers plants have these similar roots growth. Coco Coir for seed starting and seedling for a short period of time from germination to a pair of true leaves are so good for me in very small containers. It gives very healthy roots for the young seedlings. The pots size (not plastic pots) are about a medium size egg the medium is coco coir. I got very good result. "Growers mixing potting soil with considerable amounts of coco coir can end up with a large percentage of male plants." One of my plants have no flowers, how much coco coir I used I cannot recollect. Because I had a lot of coco coir and I did not like to throw it away so just I used it. From the quoted text about perlite, quality horticultural grade soil and the no.4, I agreed. In EU many of us enjoy store bought horticultural grade soil for our container plants (chili plants). I requested for their opinions about container medium, I got the opinion as I mentioned. Some of them mix a bit perlite and cat litter. No. 3, male plant or not, I do not like to use considerable amounts of coco coir in my growing medium because it is water retentive. The text is from "Marijuana growing" tips you are right Nc-crn. I do not have any negative comment on "Marijuana Growers" I hope they are also give a lot of attention to achieve their goal just like we do. About sand in container medium, I never tried. Jean001 the tips is from marijuana growers site. Some of the points are useful for my chili plants too. Thank you again for both of your time and posts :-). Caelian

Well, I checked my bags of potting mix, but neither of the open ones have the moisture retention feature. I did buy one or more with that feature, though, so it's possible that's what I used in those little pots. Still, I'll continue to observe the "egg." This could turn into a blonde joke.....