Hi Lorna,
Here's T&M's growing instructions:
Sowing Instructions: Sow March to May, thinly, 12mm (½ inch) deep in drills 30cm (12 inches) apart in well cultivated soil raked to a fine tilth. Germination usually takes around 21 days.
Growing Instructions: When large enough to handle, thin seedlings to 30cm (12 inches) apart. Alternatively, you can sow indoors in late winter/early spring for earlier flowering. Sow individually into 7.5cm (3 inch) pots at 20-30C (68-86F). When well grown, gradually acclimatise to outdoor conditions before planting out after all risk of frost.
Aftercare Instructions: Prefers a well drained soil in full sun. Flowers mid/late summer to autumn.
I sow mine in pots on the windowsill, germination is much quicker. Once they are about 1 1/2 - 2 inches high, I grow them on in my mini greenhouse until planting time. Watchout for slugs though, I lost 6 dwarf sunflowers due to them even though the seedlings were in my mini greenhouse. Vaseline on the pots is a great deterrent but make sure the slugs can't get to your seedlings from other plants.