I have been studying what makes a good container mix...and there sure are many recipes! One thing is critical: drainage. Having a container that is muck on the bottom 4 inches smothers the plant and leads to death. Some people think putting gravel, glass, or even broken pottery around the holes helps. It is not true (seems like it should help...huh?). I will not get into the details and science behind why this happens...just know it does. We all have pulled out "mucky" plants that were dying....right? Creating a mix that is "free draining" simply involves eliminating small particles that plug up the mix. Adding larger particles like perlite, pine bark, gravel, etc....does not help a mix with small particles (like garden soil). How many bb's does it take to make pudding drain??? You get it....right? Adding a wick that is in the bottom of the mix and extends out the bottom hole is a great answer. Simply explained...the cohesive tension shared by the wick and the mix "fools" the mix into "thinking" the pot is deeper. Thus, perched water continues to drain. Not the scientific explanation...but you get it.
Today I planted many containers for my tomatoes using differing amounts of: pine bark (orchid bark), perlite, compost, amend, peat moss, and palm/cactus potting mix. I wicked most of my pots, as well.
Whatever you do...do not use MiracleGro "Moisture Control". It makes the muck factor worse (maybe for hanging baskets I suppose). Happy Spring!
