Better germination rate at lower temperatures. At higher temperatures, germinates faster but at lower rate. For best germination, sow at 15°C.
Try to aim for a seed spacing of at least 3.12 inches (8.0 cm) and sow at a depth of around 0.2 inches (0.5 cm). Soil temperature should be kept higher than 8°C / 46°F to ensure good germination.By our calculations, you should look at sowing Norfolk about 60 days before your last frost date.