Adenium Not Growing . Led grow lights do not need special lamps. Wait until march and no later than june to start growing adenium seeds. How to Grow Adenium Obesum Garden Guides from www.gardenguides.com However, since they are low wattage you need them close to the desert rose plant. You can make it own 1 part of coir peat, 1 part of the soil and 1 part of perlite, and mix a small part of sand. This is a very important factor for proper flowering.