Iris Germanica or Bearded Iris have large blade like leaves and large flowers, the flowers have a beautiful structure, three upper petals and three lower petals, the lower petals have soft hairs at the top which gives the name “Bearded Iris.
Iris Siberica are slimmer family members the flowers are beardless, no hairs on the flowers they have a more delicate look to them Iris Siberica love the sun but will tolerate partial shade they will also take more moisture than Germanica although they do not like waterlogged soil, the leaves are more grass like unlike the thicker fleshy Iris Germanica and they will tolerate any soil from light to heavy. Iris Germanica and Siberica are easy to grow, plant in a sunny position where their rhizomes can bake in the sun, don’t plant with ground cover plants as they can hide the rhizomes from the sun.
Bearded Iris like a soil with good drainage they like a neutral soil but will cope if the soil is chalky or alkaline, if you have clay or heavy soil add in some grit to help with the drainage. Our iris are bare rooted if you can’t plant straight away put in some damp compost otherwise give then a light soak to plump up the rhizomes and plant at soil level spreading the roots a little; give them about 30cm spacing, give them a good high potash feed while they are growing always avoid high nitrogen fertilizer, once the flowers have faded bone meal will give them a boost to help see them through the winter.
Iris Germanica (Bearded Iris) and Iris Siberica are excellent perennial plants perfect for the middle to back of the border where these statement perennial plants can bring pazzaz and a little of the wow factor; Iris are ideal for the cottage to the modern contemporary garden and because they divide so easily are excellent value for money.
When the Iris have established after 3 to 4 years you can divided the Iris to make new plants this also stops them from becoming woody which results in fewer and fewer flowers, dig the clump up after flowering using a sharp knife to cut away the leaves to a fan shape around 15 cm in length, each piece should have a portion of the rhizomes around 15 cm long, if the rhizome looks withered they are best discarded.
Their are not too many problems to look out for but keep an eye out for Rhizome rot this usually shows in the late spring, the first signs of rot start at the base of the stem and travel into the rhizome once infected it will become brown and soft with a distinct rotting smell, as soon as you see this cut away any patches back to good clean root and dust with fungicide.
Grey mould is another problem you should look out for although it is easy to spot it’s a fuzzy off white or greyish brown spore usually in the leaves, it is vital you do not disturb the plant to much and release the spores in to the air to infect other plants a good idea if to use a fleece cover the iris to help prevent the airborne spread. Cut back and burn any infected growth and treat the plant with an appropriate grey mould fungicide, slugs, snails and thrips can also be a problem.
Once planted all you have to do is sit back and wait for the show.