Sow the seed thinly in pots or trays on a windowsill or in a greenhouse in a good quality, finely sieved, moist compost.
Look to ensure a distance 1.95 inches (5.0 cm) between seeds when sowing - bury at a depth of at least 0.23 inches (0.6 cm) deep. Soil temperature should be kept higher than 15°C / 59°F to ensure good germination.By our calculations, you should look at sowing Bonita Carmen Double about 49 days before your last frost date.
Transplant seedlings spacing them 5cm apart in trays and grow on. Acclimatise the plants to outside conditions and then plant 15 – 23cm apart in a sunny place.
Ensure that temperatures are mild and all chance of frost has passed before planting out, as Bonita Carmen Double is a half hardy plant.