I once tried to reuse the potting mix but none of the plants really did well that year. I didn't bother taking 1 photo all summer in fact. The soil is completely filled with roots, to the point that I have to saw through it to break off chunks of soil to be able to pick them up and toss them in fall.
I've got 40 containers each summer of annuals. I've been using Miracle-Gro regular mix and their Moisture Control in the past, and both are pretty good, I really have no complaints about either. I get the 2 cu ft size bags, and I always wait for a good sale though, but with Covid, it seems even the good sales aren't that great anymore. The 2 cu ft bags are $13.99-$17.99 for their regular mix and $16.99-$18.99 for the Moisture Control. Past sales I've gotten their regular mix for $8.47 each, and I need about a dozen bags. Plus our sales tax is over 10%, so it really adds up.
I've looked into buying separate ingredients and mixing my own, but the prices turn out much higher in my area, mostly because of those separate ingredients being sold in smaller packages, plus I don't really have the room to be mixing my own without making a huge mess.
This year I'm pretty decided on trying Pro-Mix Premium All Purpose Mix, the value size of 2 cu ft is $14.98 most everywhere here (the size that expands to 4 cu ft, or at least 3.5 cu ft from reviews I've read). And mix in some earthworm castings with my usual slow-release fertilizers. That's not a sale price, I can hope for a sale once everyone gets them in stock, but that's not a bad price considering it expands to near double the size.
So I've been wondering what everyone else uses, and is there a cheaper way? For me that's over $100 I could spend on more flowers!
