Gardeners tend to assume that phormiums are drought tolerant, which is true to a certain extent, but they actually look their best when watered regularly (that is, when the soil is dry). 'Alison Blackman' phormium is one of the medium-sized varieties, topping out around four to five feet and about as wide at maturity. Upright, olive-green leaves are variegated, with a red margin, and take on a bronzy tone. An excellent container planter choice, it is also an impressive specimen. Phormiums can handle hot exposures and provide year-round evergreen interest.