Iris: Siberian Iris
Love iris but your yard is too wet? Forget the bearded iris. You need Siberian iris (Iris sibirica). It prefers moister soil than the drought-loving bearded irises. You can even plant it along the sides of streams or as part of a rain garden.
Contrary to their name, Siberian iris are not originally from Siberia which is too cold for them to grow. Their native habitat stretches from northern Italy east to Turkey and the Caucasus. After the Europeans colonized North America, Siberian iris naturalized in Canada and the Eastern United States. They have a long garden history, having been in cultivation in Europe since the Middle Ages.
Siberian iris are known as beardless iris. Their flowers are smaller and lack the fuzzy “beard” of their taller cousins. Their leaves are slender and more grass-like. They bloom towards the end of the “iris” season in late May and early June. They come in all the same colors as bearded iris, although most cultivars are blue or purple. They range in size from 12” to 40”.
Siberian iris prefers full sun but will tolerate partial shade as long as they get a few hours of full sun each day. They like moist, well-drained soil that is more on the acidic side. Don’t allow your rhizomes to dry out before planting them. Soaking them overnight before planting is a good idea. Plant them so that the tops of their rhizomes are at least one inch below the soil surface. Keep your plants well-mulched to make sure that the soil remains cool and moist. You can fertilize them with a balanced fertilizer such as 10-10-10 twice each season, once in the spring before they bloom and then again about a month after they bloom to help them replenish their rhizomes for next year.
There is no need to deadhead your Siberian iris after they bloom but you might want to do so to prevent them from going to seed. Siberian iris can be grown from seed. If you allow their flowers to mature into seeds, they will reseed in your garden. Since they also multiply vegetatively, you might want to prevent them from reseeding themselves, encouraging them to use their energy instead to grow their clumps so that you can divide them into new plants.
You will notice that your iris clumps expand outwards each year until eventually the centers stop blooming. You should divide your clumps before they reach that point which is unhealthy for them. Spring is the best time to divide and replant your iris. Divide them be carefully digging up the rhizomes about a month after they finish blooming and cutting them apart. Replant the outermost, young rhizomes and discard the older center ones. Replant them with the tops at least one inch below the soil surface. If you are not going to be replanting your rhizomes immediately, keep them moist by storing them in bucket of water until you are ready to plant them. Smaller divisions can take up to two years to reach a size where they will bloom so be patient!
Iris make excellent cut flowers. Harvest your flowers early in the day. Choose buds that are just beginning to open rather than flowers that are fully open. The buds will open in a few hours in the vase. Place your flowers in a bucket of tepid water until you are ready to create your arrangement. When you are ready to arrange them, re-cut the stems about an inch above the original cut at an angle. To ensure the longest life for your flowers, keep your arrangement out of direct sunlight. It’s also a good idea to place it away from drafty doors and windows. Be sure to remove dead and dying flowers promptly.
Siberian iris are smaller, more delicate versions of the stately bearded iris. They are easy to grow, relatively disease free, and don’t mind moist areas. They are a good choice if your yard is not suitable for bearded iris.
© 2015 Caren White