Last week I had a post featuring an oustanding container garden with so many plants growing it seemed impossible. Perhaps the secret to a great container garden is the foundation--the soil! Pat and I are great at the one-plant-per-pot style of container gardening. But as much as I've tried, I cannot seem to get several plants going at the same time in one container.
This is the basic potting soil recipe I found on Fine Gardening:
1 part peat moss
1 part perlite
1 part compost
1 part good garden soil
A handful each of:
Moisten the ingredients to make mixing easier. Place a ½-inch mesh screen over a garden cart or other large container, and sift all ingredients to remove any large particles. Mix thoroughly.
The handfuls of garden lime, soybean meal, rock phosphate, and kelp meal (any of which can be omitted) provide extra nutrients that enable this mix to feed plants for a year or two without additional fertilization.
Go to this link, and there are several styles of potting mix for specific plants such as cacti and annuals.
Another favorite gardener of mine is The Patient Gardener who lives in England. She has a post on a simple container garden that can probably be planted right now!