Hello everyone,

I have two large window boxes in front of my house. When I planted the boxes, I made up a custom mix of 1/3 commercial potting soil, 1/3 of my homemade sifted compost, and 1/3 peat moss. I added the peat moss to lighten the mix and to aid with water retention.

Well, fast forward to now and the mix is very hard to water. Based on what I have read since i did this, the peat moss is dried out and does not hold moisture anymore.

Commercial mixes are very heavy when wet, and I am concerned about the weight of the box breaking its supports. Does anyone have a good recipie for a light (in weight) mix that can be used for flowers?