How deep can the purpureum's be planted we have here 10 cm frost in the ground in winter rarely 20 cm without any cover Roland 2011/11/29 Robert Hamilton <roberth6@mac.com> > Hi Roland, > > -- R de Boer La Maugardiere 1 F 27260 EPAIGNES FRANCE Phone./Fax 0033-232-576-204 Email: bulborum@gmail.com