Iris pallida aka Sweet Iris

Iris pallida is a perennial in the iris family, Iridaceae. Gardeners call it Dalmatian iris or sweet iris. It comes from Dalmatia in Croatia and the southern Alps. Its range includes northeast Italy and parts of former Yugoslavia. It grows on rocky limestone slopes and beside gorges. The plant forms upright clumps from rhizomes and keeps some leaves through winter.

Garden plants reach about 1.6–3.3 feet [0.5–1 metre] tall. Clumps spread about 0.3–2 feet [0.1–0.61 metres] wide. Flower stems can reach 3.3 feet [1 metre]. The sword-shaped leaves grow to about 2 feet [0.6 metres]. Their colour ranges from green to greyish blue. The stems branch and carry two to six flowers. Dry, pale, papery bracts surround the emerging blooms.

Flowers open from May to June, spanning late spring and early summer. They have a sweet scent and pale lilac-blue petals. Yellow beards add a clear contrast to the petals. Each flower measures about 0.25–0.42 feet [0.08–0.13 metres] across. The flowers suit cutting, as well as beds and borders. Clumps also fit cottage gardens and open woodland gardens. Sources list the plant for ground cover and deer resistance.

Give this iris fertile soil that drains well. Loam or sand with neutral to slightly acid pH suits it. Full sun gives the best growing conditions. It also tolerates partial shade better than many other irises. Deep shade and heavy, wet soil lead to poor growth. Moist soil suits it, though established plants withstand some drought. Sources place it in USDA zones 5–9 and UK hardiness class H7. Divide clumps in late summer when needed. Seeds offer another way to raise new plants. Cut spent flower stems and remove dying leaves in autumn.

Serious pest and disease problems are not usual, but damage can occur. Iris borers, slugs, snails and thrips may attack plants. Aphids can spread viruses. Bacterial soft rot and grey mould can also affect it. Dried roots provide orris powder and oil for scent and flavouring. Their scent can take several years of drying to develop. Uses include perfume, toothpaste, sweets and drinks, along with a black dye. Historical medicinal use includes a strong purgative made from fresh root juice. These uses do not mean the plant is safe to eat. RHS warns that eating it harms both people and pets. Wear gloves and protective clothing when handling it.