What do all you Geranium (Pelargonium) experts use for potting medium for your geraniums? I think mine is too water retentive because I keep getting some rot in my large plants and my cuttings. I welcome all advice; thanks Lynn
After growing Pelargoniums for several years I do not regard myself as an expert.
This problem has become worse in UK because of the reluctance of many growers to use peat.
The peat substitutes most commonly used, in UK, are coir and bark both of which are very moisture retentive. If you do not wish to use peat based potting compost then I suggest that you use sterilised loam-based composts and horticultural grit to improve drainage. Do not allow your plants to become waterlogged. Regarding cuttings; I have used several different media to root pellie cuttings without problems including peat discs (Jiffy 7s)or sterilised loam/perlite mixtures. Two important points:
1) Do not tent or close-up the cuttings
2) Do not use rooting powder or gel, this can cause pellie cuttings to rot.
Hope this helps