Hi Irene24, this is a half hardy perennial usually grown as a biennial, as it deteriorates in the second year of flowering, it will need protection of a heated greenhouse in winter, Derek.

I am growing a different variety and I just sprinkled them on the compost and covered it with vermiculite. they are now in small 'clumps in individual pots getting stronger by the day.

Thanks both what can you use instead of vermiculite?

fine compost, sand, perlite.