My double impatiens... bought a whack of em. The only ones that I bought that were the "same" as last year were the Burgundy. Thre others were all "new" varities which grew very slowly and were late to bloom. They are still only half the size of the Burgundy and a few are not blooming well. I always buy a three spares and put them in a hanging pot. The Burgundy is fine but the other are smaller abd STILL have not bloomed... what can I do to make them bloom?