How to Grow Reblooming Bearded Iris
Reblooming Bearded Iris are the darlings of the cottage garden world — they bloom profusely in an amazing range of colors/color combos, throw out a delicious fragrance (grape soda, anyone?), and are ridiculously easy to grow. And that swordlike foliage remains after the blooms have faded, leaving a strong vertical presence in the garden. It helps that they're practically bulletproof, too.
Ready to add some easy care charm to your garden no matter where you live? Here’s everything you need to know.
How to Plant Reblooming Bearded Iris
Bearded iris needs are few — meet them, and you’ll be rewarded with an abundance of blooms year after year. They grow not from tulip-like bulbs, but from rhizomes or fleshy tubers that are planted close to the soil surface in USDA Hardiness Zones 3-9.
We grow our iris in some pretty tough conditions, resulting in huge rhizomes!
Time your planting
Live in a cooler climate? Plant in late summer to early fall. Those in southern, warmer climates can plant in October and November. Planted too late? Don’t worry too much — the iris will likely still bloom in the spring, but may need a little catch-up time to perform in their full glory.
Choose your location
Bearded iris prefer full sun. And while they will bloom in a wide range of soils, the #1 rule is that the soil must be well-drained — soggy soil will rot out those rhizomes faster than you can shake your fist. Work some organic matter into the top 2 – 3” of soil to improve your drainage, and you should be good to go.
Plant the rhizome.
If you’re planting multiple rhizomes (and you should, because you’ll want as many as your garden can handle), space them 8 – 12” apart. Dig out a shallow trench and lay your rhizome horizontally on the soil surface, making sure that any existing leaves are placed in the direction you want the growth to go. Now, gently replace the soil around the edges of the rhizome so that the top is peeking out — and again, if you live in an area with very strong sun, feel free to cover the top of the rhizome with a scant ½” of soil.
Gently soak the soil with water, allowing it to settle the rhizomes down into place. Now, here’s where you’ll need to back off a bit — your bearded iris won’t need much water at all until you see actively growing new leaves. If you feel the need to water, do it sparingly.
Tip: If you want to plant bearded iris in containers (You should — it’s quaint and lovely!), be sure to choose a container that is at least a 2-gallon size or larger to accommodate growing and spreading rhizomes. Use barrels, urns, and galvanized troughs, making sure they all have adequate drainage holes.
How to Care for Bearded Iris
When your iris is in active growth and blooming, water regularly, but make sure the soil dries out a bit in between. After the blooms have faded, continue watering regularly for about 6 weeks — this aftercare ensures that your bearded iris continue to “clump out” and form buds for next season’s bloom.
Right about now, you may be wondering about fertilizing. We suggest using a low nitrogen fertilizer such as a 5-10-5 mix. Fertilize in early spring and again after blooming by scratching the fertilizer into the soil around the rhizome. (Do not let the fertilizer touch the rhizome.)
How to Divide Bearded Iris
As your bearded iris grows, the original rhizome will clump out and produce more rhizomes. More rhizomes = more leaves and more blooms, but after awhile, the original one will die out. It’s at this point you’ll need to divide your irises, about every 3-4 years. Here’s how you do it:
- Using a garden fork or spade, carefully dig up the rhizomes, using caution so as not to cut them up unnecessarily.
- Decide which rhizomes to keep and which to compost. A keeper will be as thick as your thumb, with visible roots and 1-2 leaf fans. Large, soft rhizomes with no leaf fans? Feel free to toss ‘em.
- Gently rinse soil off the rhizome, looking for a fat, white worm called an iris borer. When you spot one, remove it and feed it to your chickens if you have them.
- Cut leaf fans to 4-6” long.
- Replant rhizomes using the steps in the first section above, only this time, fan out the roots lower in the soil than the rhizome itself, and gently cover with soil.
How to Deadhead Reblooming Bearded Iris
Feel free to snip off blooming stems throughout the season (spring, and again in the fall) — they’re lovely as cut flowers in arrangements. Cut the stem at the bottom where it meets the fan of leaves. After the blooms have faded on your plants, cut off the spent flower stems, making sure to get down to the visible base of each stem. Remember to leave the foliage alone, though — the leaves gather sunlight and store it for next year’s flower display.
Never tie the leaves together!
Beautiful Reblooming Bearded Iris 'City Lights'
Once you start growing reblooming bearded iris, it may become your new passion — there are so many fetching color combinations that you’ll itch to add them all to your garden. Plant groupings of the same variety to create an impact, and add in other flowering perennials and annuals for nonstop bloom.
Want to plant an outdoor rainbow? Try our Bearded Iris Califlora colorful mix!
- Katie Elzer-Peters