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Pot-grown bearded iris plants
Trowel or spade
Finding plants to grow in a hot, dry border can sometimes be tricky. Bearded irises will thrive in these conditions, and require very little care or watering once their roots are firmly established.
Bearded irises only flower well if their rhizomes get baked in full sun, while their grey-green leaves reflect the heat, helping to reduce water loss. The flowers come in a range of bright and exotic colours, and they bloom from mid-May to mid-June.
The best time to plant bearded irises is from June to October, for flowers the following year. Immediately after flowering is the best time to lift and divide existing clumps. Irises come in three main sizes: dwarf varieties, which are about 15cm tall; intermediates, which reach 60cm in height; and tall varieties, which grow up to 1.2m. With such a wealth of options, you can usually find a variety to fill any gap in a sunny border.
Choose potted irises carrying several clusters of healthy leaves. Lift out of their pots and look for healthy roots.
Dig a planting hole that is just deep enough to take the rootball. Choose a sunny site with a well-drained soil. You can improve drainage in your soil by digging in plenty of grit before planting.
Settle the rootball into the hole so it's level with the surrounding soil. Backfill with soil, then firm around the plant. Achieve the best effect by positioning plants in bold groups, with multiples of the same variety growing together.
Ensure the rhizome is on the surface of the soil and not covered with soil, so it's exposed to the sun. Trim neighbouring plants, if necessary, so they don't cast shade over your irises.
Water the whole area thoroughly, to settle the soil and remove air pockets. Only water again if the soil is very dry. Feed early in the season with a low-nitrogen fertiliser such as bone meal.
Mulch the soil with gravel, to retain moisture, but don't cover the rhizomes. Deadhead irises after flowering by cutting stems back to the fan of leaves. Plants will bloom again next spring.
Choose a position in full sun, where the iris flowers will show up against a plain background – an evergreen shrub, hedge, brick wall or painted fence are ideal.
Weed regularly by hand, to stop them taking hold. It's impossible to hoe round iris without damaging the rhizomes, so don't try.
30/08/2013 at 17:11
I have grown some irises from seed. They are looking good, healthy and happy. However, they have roots, no rhizomes. Is this because they are young?
30/08/2013 at 20:52
I think so, Mandy. The rhizomes are a sort of food store and yours haven't had time to build that up yet.