Out of the Unknown S01 E06 Come Buttercup, Come Daisy, Come... ?

Henry Wilkes cultivates rare tropical plants as a hobby; with an attention to detail which is, perhaps, closer to an obsession. The length to which he goes to propagate and nurture new hybrids alarms his wife. Is there more going on in the greenhouse than could safely be exhibited at the next Battersea Flower Show?