I have to admit, I find the month of August extremely enjoyable for two opposite reasons: on the one hand, I love the summer and the beautiful weather August can typically bring, but on the other, I love the fact that autumn is not fall off. As long as the winter can get here in the upper Midwest, there is something comforting to me about the day that I pull out my favorite sweater, pack away the shorts, and throw a log on the outdoor firepit for the first time.
Since this month of August is now upon us, I’m beginning to plan the location where I’ll be planting my bearded iris. One of the first fall-planted “bulbs” (technically a rhizome) available and also one of the first that should be planted, bearded iris are possibly one of the most elegant, well-loved, and easily recognized blooms in the spring garden. While reading various articles written about this plant, I find it interesting that some refer to it as “extremely easy to grow” and others warn against its difficulty level. I feel as though bearded iris are not any easier OR more difficult than any other plant. Simply follow the tips below for planting and dividing and you’ll have a successful iris garden as well!
Planting
- Bearded iris should be planted during the late summer and early fall months. For most of the United States, this time period ranges from early August to late September. Unlike many of the other fall bulbs, iris rhizomes require a good establishment prior to the onset of frost.
- Bearded iris should be planted just below the soil’s surface. One of the biggest killers of bearded iris is excess moisture. You can avoid this by being careful to only lightly cover the rhizome with soil. If “fans” of the previous season’s foliage are still intact (as most rhizomes are harvested), allow this foliage to stick up out of the soil.
- Plant in a sunny, somewhat dry location. Iris should receive at least 6 hours of sun per day. More than 6 hours is better as it will help to keep the rhizome dry.
- Space rhizomes to allow for good air circulation. Iris rhizomes should be spaced at least 12-18″ apart (a tad closer if planting dwarf varieties) to allow adequate air flow between the plants. Avoid mulch directly over the rhizomes to allow air to reach the soil surface.
- Fertilize twice per year for best show of flowers. Apply a granular fertilizer once in the early spring and then once after flowering.
- Keep plants clean. Remove flower stem and seed pod after blooming. Cut remaining foliage within 4-6″ of the ground’s surface in the fall.
Dividing
Unlike most fall planted bulbs, bearded iris require dividing once every 2-4 years in order to continue to perform at their peak. This is best done in the late summer, just as the weather begins to turn cooler. Follow the tips below for a successful dividing experience.
- Be careful not to damage or accidentally cut the rhizome while digging. Dig around the rhizome with a garden fork, leaving enough space between the fork and the rhizome as to not accidentally damage the rhizome.
- Look for “branching” or segmented sections of the rhizomes to divide along. Divide the rhizome by breaking with your hands whenever possible. Using a sharp knife or garden pruners is also on option but can spread disease. Attempt to keep all sections of rhizomes at least 3″ in length.
- Inspect rhizomes for health and overall condition. Discard of and remove any parts of the rhizomes which are hollow, soft, contain borers (white insects), or have a undesirable smell.
- Cut foliage within 4-6″ of rhizome. Remove any rotten or damaged foliage by clipping it off shorter than the 4-6″ if necessary. Replant rhizomes as above.
I tend to consider gardening my therapy for dealing with the change of seasons: with each new season, comes a new adventure in the landscape. Perhaps you can look to fall with joy this year as you plan your bearded iris garden! I know which iris are MY favorites 🙂
Have a comment to share with other readers? Feel free to post below. Have a question specifically for Bridget? Feel free to email her at bridget@bulbblog.com!
