Agapanthus Shades of Grey - 10 FRESH SEEDS - Free UK Delivery. Photos show my parent plant in flower. I Sow Agapanthus seeds in shallow pots containing a good quality seed compost with some horticultural grit or perlite to improve the drainage. Sprinkle Agapanthus seeds on top of the soil and keep compost damp but not wet. Make sure the pot gets good light - at least 6 hours of sunlight per day and a temperature of between 13-15 degrees Celsius. When they are large enough to handle, prick out the seedlings into individual pots. Overwinter these under protection so that they are in a frost free environment and then they will be big enough to be planted outside in the following spring.