My personal favorite primrose. This sieboldii selection blooms later than others but the flowers which are soft blue on the back of the flower and have a pure clean white face on the front. Heavily frilled petals are elegant on 8″ stems. Blooms May to early June in cooler years. No other cv of P. sieboldii comes as close to true blue. Forms a clump in time in rich, moisture retentive soil in part shade. Goes quickly summer dormant with true heat. Still water the roots of the dormant plant- they like that and will reward you with a greater show the following spring.