Iris xiphium hybrids
Family: Iddaceae

Although known as Dutch iris, these hybrids were developed from the Spanish iris, I. xiphium, and other species. Widely grown as a cut flower, Dutch iris is a lovely garden subject, especially when planted en masse in solid blocks of colour. It also makes a good container plant. The deep violet blue is probably the most popular colour, but it also comes in golden yellow, white and other shades of blue and violet. All have a yellow or orange blotch on the petals. The flower stems may be more than 50 cm (20 in) high in good conditions. Dutch irises flower in the spring and summer. There is a range of lovely forms and colours.

Cultivation

Dutch irises need full sun, with some protection from strong wind. The soil must be well drained, with decayed compost or manure dug in a month or so before the iris are planted. Plant the bulbs in autumn, 8-10 cm (3-4 in) apart to a depth of 5 cm (2 in). Mulch soil surface with rotted manure or compost after planting. If soil has been well prepared, little or no fertilizer will be needed. In poor soil, a little blood, fish and bone can be applied once the leaves emerge. Water well after planting, then withhold water until the foliage appears. Give deep, weekly watering during the growth and flowering periods, and cease all watering once the foliage starts to die down. Bulbs may be left undisturbed for several years or until the floral display begins to deteriorate. If you wish to lift the bulbs, do so as soon as the foliage dies down and store the cleaned bulbs in a dry, airy place. Few problems are encountered by home gardeners but bulbs will rot easily if overwatered or if the soil is poorly drained.

Climate

Zone 7.