Jennifer, I've belonged to GWeb for a long time, and most of the wintersowers there use Miracle Grow, though usually not the moisture control one. Most nurseries don't seem to keep the professional potting mixes (ProMix, Fafard, MetroMix) on display. Most only have MG on display for sale to customers. But if you ask what they use for their own growing, it's always a professional mix. If you ask, I've found all of them willing to sell me a bag or bale. Another good place to find them is hydroponics stores.
My real problem with watering is absolute negligence. I let things die of thirst way too often. This year my coleus cuttings have barely limped through alive due to repeated drying and leaf drop. I repotted them, adding some expanded shale and I see a noticeable improvement. Expanded shale retains moisture, retains oxygen, drains well. It's only been a few weeks but so far I'm impressed by what I see.
Expanded shale
The thread "Expanded shale" in
All Things Gardening forum
Karen
