Quote Originally Posted by TwinShadows
place rock "Lava or river rock is fine" an inch high at the bottom of the pot.

This will allow air to reach under the soil and also keep roots from sitting in water at the bottom of the pot. perlite or something like it is a must, it helps water drain and keeps the soil from turning into mud.
Great advice. Added advice is:

Place a water collection tray under the pot and keep it 1/3 to 1/2 full. This will allow the lava rock to remain wet/moist.

This will keep the grow medium and the bottom roots from drying and growing looking for new water.

The plant roots will grow into, under and around the lava rock, encasing it and having it become part of the rootball.

This will allow you to grow larger plants in smaller pots as well.

The lava rock and dust are high in minerals as well and will lessen the need for ferts long term.

The debate about Miracle Grow rages on. Some are sold on it, others despise it.

I think there are far superior grow mediums for plants than Miracle Grow...unless you grow tomatos.