I love irises of all kinds, and the reblooming beardeds, Iridaceae germanica, in particular. These send up ruffled fleur-de-lis not only in spring, but in early autumn, too. Just now a clump of alabaster-white ‘Immortality’ (above) is in flower beneath the Yoshino cherry tree in my Serpentine Garden, a glowing vision at a time when my other perennials are beginning to wane.
Like all bearded irises, the reblooming varieties have three definite requirements: good drainage, plentiful sunshine, and early-autumn planting. The rhizomes need 5-6 weeks of rooting time to establish themselves before the ground freezes. Denied this pleasant rooting period, they may still survive the winter, but they will wait until fall, not spring, to set their first flowers. Be sure to plant the rhizomes with the top of the fleshy roots only half an inch or so under the surface of the soil. For the best blooms, give the plants a light sprinkling of bone meal in the fall, and of a balanced fertilizer when new growth appears in spring.
You will find among the twice-blooming beardeds a tremendous variety of color, from peaceful pastels to screeching red-and-yellow bicoloreds. For both garden and vase, I prefer the single-hued whites, blues and purples. In a mixed border, repeated groups of just a few varieties are far more effective than a nervous blend of numerous kinds.
Indispensable and irresisible are:
‘Immortality’ – white; sweetly scented, hardy in zones 3-9
‘Cloud Ballet’ – icy-blue, fragrant, zones 5-10
‘Feed Back’ – violet-purple, zones 5-9
‘Rosalie Figge’ – reddish-purple, perfumed, zones 3-7
‘Forever Gold’ – cheerful yellow, zones 3-8
If I were you, I’d find room in my garden for at least one of these sturdy performers. For the twice-blooming iris gives the flower bed weeks of rich, pure color, and its sword-like foliage provides architectural interest throughout the growing season.