How to plant irises Germanica and irises Sibirica

Perfect for the middle to the back of the border, irises Germanica and Sibirica are excellent statement perennial plants that will bring pizzazz and a little wow factor to your garden, from the cottage style to the modern contemporary. They also divide quickly and are, therefore, excellent value for money.

Irises Germanica produce large blade-like leaves and large beautifully structured flowers composed of three upper and three lower petals, also known as falls. The base of these falls is peppered with soft hair, a quality that has earned these irises the common name of Bearded iris.

How to grow irises Germanica and Sibirica

• Plant in a sunny position where their rhizomes can bake in the sun
• Avoid planting them with ground cover plants as these might hide their rhizomes from the sun
•  They like soil with good drainage, and although they prefer neutral soil, they will cope if the soil is chalky or alkaline
• If you have clay or heavy soil, add some grit to help with the drainage.
• Irises Sibirica are slimmer family members. Beardless and sporting a more delicate look, they love the sun but will tolerate partial shade. They will tolerate any soil from light to heavy, and although they do not like waterlogged soil, they will absorb more moisture than irises Germanica. Unlike the thicker, fleshy irises Germanica, their leaves are more grass-like.

Aftercare

• Our irises are bare-rooted, so if you can’t plant them straight away, put them in damp compost or give them a light soak to plump up the rhizomes before spreading their roots a bit and planting them at soil level.
• Space them about 30 cm apart, and feed them a high-potash feed while they grow. Avoid using high-nitrogen fertiliser.
• Once the flowers have faded, bone meal will give them a boost to help see them through the winter.
• Once the iris has been established for 3 to 4 years, you can divide it to make new plants. This will also prevent it from becoming woody, which results in fewer flowers.
• After flowering, use a sharp knife to dig the clump up and cut away the leaves to a fan shape. Each piece should contain a portion of the rhizomes approximately 15 cm long. If a rhizome looks withered, discard it.

Potential problems, pests and diseases:

There are a few problems to look out for but watch for rhizome rot. Usually showing in late spring, the first signs of rot appear at the base of the stem before travelling into the rhizome. Once infected, the rhizome will become brown and soft, giving off a distinct rotting smell. As soon as you see this, remove any patches, return them to a clean root, and dust them with fungicide.

Grey mould or botrytis is another problem you should look out for! Easy to spot, its fuzzy off-white or greyish-brown spores usually appear in the leaves. You mustn't disturb the plant too much as it will release the spores into the air and will infect other plants. A good idea is to use a fleece to cover the iris to help prevent the airborne spread. Cut back, 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.

Iris flower in late spring along with alliums and camassia and make company for these tall flowers.