Twice the Bloom, Half the Work: The Magic of Reblooming Iris
by Ken Lain, the mountain gardener
McKenzie Lain, Watters Garden Center general manager
My grandmother's garden was famous for its iris beds. Growing next to the Prescott National Forest, they were a magnificent spectacle each spring. I believe it was one of the few flowers the javelina and deer left alone. She always said the iris's superpower was how they hugged the surface of the garden, a trick that kept their blooms spectacular. She replanted her beds every 2 to 3 years to ensure the rhizomes were always positioned perfectly. I want to share her insider tips with you in this column.
When your iris bed gets crowded, it's time to replant. A good rule of thumb is to check every 3 to 5 years for spring-only blooming Iris, or when the flowers become smaller and fewer. Reblooming irises need to be replanted every 2-3 years. This is a simple project that guarantees bigger, brighter blooms.
Why Reblooming Iris are a Must
When you replant, only use reblooming varieties. Regular bearded iris bloom once in the spring, and that's it. Rebloomers give you a spectacular show in spring and again in late summer or fall. Many rebloomers will even continue to send up new flower spikes until the first hard frost. This second round of blooms is why they are my favorite.
Top 10 Iris Varieties
Freshness matters with bulbs, which is why I've partnered with the best farm to give you direct access to a friend's Iris fields. The Watters horticultural team has personally curated the Top 10 Iris Varieties for local gardens. Each is famous for its vigorous reblooming ability, sturdy stalks, and mountain hardiness against wind and drought. These are stunning, new colors ready to take root in your garden. Iris are ready to plant now. Take a look at the Watters Prescott Iris collection.
When Your Iris Reverts to 'Prescott Purple'
Many gardeners believe their fancy yellow, pink, or white iris "reverts" back to the common purple, but this isn't a genetic change; it's a matter of competition. The common purple iris, often called 'Prescott Purple', is a tough, vigorous plant that multiplies faster and outcompetes the more delicate hybridized varieties. Typically, a few rhizomes of this hardier type are mixed into the bed. Over time, they take over, choking out the other colors. The flowers aren't changing color; the 'Prescott Purple' has simply overrun the bed. This is why a thorough cleaning of the bed is essential, ensuring you only replant the healthy rhizomes of the specific colors you want to keep.
Dig them up. Use a garden fork to carefully lift the entire clump. Be gentle to avoid damaging the rhizomes.
Clean and trim. Shake off the soil. With a clean pair of pruners, trim the leaves into a fan shape, about 6 inches tall. This reduces stress on the plant as it regrows its roots.
Inspect and divide. Look for the fat, healthy rhizomes. These are your keepers. The ones that are soft, shriveled, or look like a shrunken prune you would find sold at a box store should be tossed in the compost pile. Use a sharp knife to cut the new, healthy rhizomes apart. Make sure each new piece has at least one leaf fan and some roots attached.
Prepare the soil. Iris needs well-draining soil. Mix one part Watters Premium Mulch into two parts of the native soil, along with a handful of bone meal. This adds a slow-release phosphorus, which is essential for root and flower growth.
Plant them right. Dig a shallow trench. Place the rhizome in the trench, making sure the top of it is just visible above the soil line. The roots should be spread out below the rhizome. Backfill the trench gently. You can plant them individually or in a clump of three for a fuller look. Space them about 8 to 12 inches apart.
All-Purpose Food & Humic Acid
To give your iris the best start, use a one-two punch of Watters All Purpose Plant Food and Humic. When your Iris are all planted, sprinkle Humic as a soil conditioner. This rich, organic material improves your soil's structure and helps it retain moisture and nutrients. It loosens up our heavy mountain soil and promotes a vibrant microbial environment, which is essential for healthy root growth. The Watters All-Purpose Plant Food is a low-nitrogen formula that provides the phosphorus and potassium plants needed for sturdy stems and abundant blooms.
Water in. Give the newly planted iris a good, deep drink. This settles the soil around the roots. After this initial watering, hold off. Iris are very drought-tolerant, and overwatering is the surest way to cause the rhizomes to rot. Water only if we have a prolonged dry spell until the first spring blooms in April.
Animals That Leave Iris Alone
When it comes to local animals, iris are usually safe. Deer, javelina, and rabbits will not eat them. The rhizomes are toxic, making them unappealing to most critters, including pocket gophers. This makes them a perfect plant for gardens that face frequent visits from wildlife.
Today, new hybrids are bred specifically for "remontancy," which is the ability to bloom multiple times. This means we get a full show in the spring, just like she did, but then we get to enjoy another round of flowers in the late summer or fall. In our mild Arizona climate, some varieties can even throw out blooms intermittently until the first hard freeze. This extended bloom season would be a true luxury to a gardener from her era.
Every Saturday @ Watters Garden Center
Join us every Saturday morning at 9:30 AM for our free garden classes, right here at Watters Garden Center on Iron Springs Road in Prescott. September is packed with valuable insights to help your garden thrive!
September 13 @ 9:30 - Unbreakable Plants for Prescott Gardens
September 20 @ 9:30 - Fast Plants for Secret Garden Privacy
September 27 @ 9:30 am – Stunning Autumn Containers Everyone Notices
Come learn something new and connect with fellow gardeners!
Until next week, I'll be helping gardeners grow better Iris gardens here at Watters Garden Center.
