Spring brings so many pleasures! Warmer weather, longer days and the bonus…flowers. Spring bulbs put on their show, then come the irises and peonies. What a disappointment when there are no blooms! How can you ensure plenty of late spring color? Possibly it’s time to divide those over grown bearded iris!
Irises of all kinds are a standard for most perennial and cottage gardens. They seem to take care of themselves, only requiring some dead heading after bloom. Japanese and Siberian iris have thinner foliage and more matted, stringy roots. Bearded varieties, on the other hand, have roots called rhizomes. They are hardy for as low as zones 3. Their large blooms bring drama and vibrant color to the landscape. The spear shaped foliage offers a contrast to the usual mound-like foliage of other perennials. Dwarf iris, a smaller type, are great for rock gardens. Just provide a sunny spot for them.
In addition to promoting blooms, dividing bearded iris can eliminate weeds that grow in the middle of the plants. This situation can turn the iris roots into a matted mess and the roots can wither or even die off over time. Division also gives you the opportunity to propagate more plants. The best time for dividing is in late summer or fall when the plant is in a dormant state. Seeds should not be allowed to form because they tend to sap energy from the roots.
To divide the iris, plunge a garden fork in under the clump. Pry them gently from the ground. The rhizomes may come free easily but if not, cut them apart with a sharp knife. Better Homes and Gardens magazine actually recommends sterilizing your knife with a 10% bleach solution between cuts. This may seem a bit unnecessary but can cut down on disease.
At this point, weeds can be pulled from in between the roots. Some sort of grass had taken over mine.
Cut all foliage to about 4-6″. This is generally called fanning.
Next, weed the area that you have excavated. Plant some of the rhizomes in a shallow hole. These roots do not like to be covered with soil or mulch. Place some soil around the roots. It’s okay to plant them with their ‘shoulders’ sticking out of the ground.
Depending on the size of your bearded iris clump, you may get three or more new clumps to replant. They can always be given to a friend or used to expand you garden space. By placing an iris in every part of your landscape, you will increase your bloom power throughout the yard.
Bearded iris benefit from a yearly topdressing of compost. If you are feeling generous, add some granular fertilizer. Otherwise, the iris in your garden will require little from you.
Bearded iris can suffer from rot from time to time. These soft, hollow roots should be removed and destroyed. Borers can also be an issue. If you see any holes in the rhizomes, be sure to destroy any of the fat, white worms if you see them!
We have 3-4 different bearded iris on our property. They make stunning additions to bouquets and pair well with peonies. Bearded iris go good with allium and lupine. The color variations are seemingly endless. If you have iris that are suffering in your gardens, why not divide them this fall season? They will repay you next spring with a bounty of blooms!
Hope you learned something about bearded iris this week! I know it seems like spring is a long ways away but this is the time to do these seasonal chores. As always, thank you so much for joining me!