Beautify your potted flowers with Miracle-Gro? Moisture Control? Potting Mix. Our specially formulated mix will feed your plants for up to 6 months and protect against over- and under- watering. It absorbs up to 33% more water than basic potting soil, so your plants can remain hydrated. Use it with indoor and outdoor container plants. Grows Plants Twice as Big!? vs. unfed plants vs. potting soil that does not contain sphagnum peat moss, coir, and wetting agent.