SOWING SEEDS is what I've been doing in late March and April. Most of the cut flowers I grow are half hardy annuals and are started off in one of my two heated propagators on a sunny window sill. I sow them in the flimsy small modules in strips of ten, 5 of these will fit into a sturdy standard size seed tray, then the tray goes into the propagator. For very fine seed I use 1/2 size seed trays. As soon as all the seeds in a tray have germinated I move it out of the propagator onto another sunny window sill for 2 or 3 days and then put them out in the greenhouse. Ideally this would be heated to a constant 20 degrees but like a lot of people I can't afford to do this so they have to take their chances! The greenhouse has an automatic roof vent and I use a paraffin heater at night if frost is threatened. Seeds that don't need a high germination temperature are started off in the greenhouse, coldframe or straight in the ground once the soil has warmed up enough.