“I tried planting bulbs (crocus, daffodils, tulips, and iris) in pots this year. They were well mulched and gathered in a warmer area of the garden near the house. Nothing came up! After investigating, it appears they became too wet and froze. The pots have great drainage. Any suggestions for next year will be greatly appreciated. Thank you!” Question from Jane of Bloomington, Illinois
Answer: Bulbs are adapted somewhat to freezing and thawing, but if they get too wet, they are prone to rotting, especially when temperatures are mild in fall and spring. There are several things that you can do to protect them from excess winter water. The easiest way is to simply store the pots under a patio or protective eave. You can also add more amendments, like Black Gold Perlite, to encourage faster drainage, but overhead cover gives one a bit more control. On the flip side, there is always a chance that they may become too dry under cover, so intermittent watering from fall to spring is recommended.
It is also advisable to protect your tulip and crocus bulbs/corms from rodents that enjoy munching on them in the winter months when food is scarce. Applying some repellent granules around the bulbs at planting time will help. From there, I recommend that you read Mike Darcy’s excellent article about creating layered bulb pots in the fall (click here to read).
“When dividing iris bulbs, how many should remain in the original site, which is around 2 x 2 feet? The iris’ are of the tall, bearded variety. They are a solid royal blue. I am uncertain of the exact variety, but they have to be an heirloom species as they were transplanted in 1950 from a family member’s garden that was started in the 1920s.” Question from Ann of Raleigh, North Carolina
Answer: How wonderful to have a garden German bearded iris (Iris x germanica hybrids) that is truly a family heirloom! We have peonies that were owned by my great great grandparents. Plants like these are irreplaceable and real treasures. Care must be taken when moving them.
A 2-by-2-foot iris clump can easily be divided into quarters, allowing you to leave a 1-foot clump behind and have three to share or move about your garden as you wish. Here are a few tips for dividing and transplanting German bearded iris properly.
How to Divide German Bearded Iris
Trim back any old flower stems or dead leaves. This makes the moving process easier.
Dig beneath and gently lift the bulbous roots–removing 3/4 of the clump, in your case. Because German bearded iris roots are large, rhizomatous, and half-exposed along the soil surface, dig beneath them and break away the roots of clumps at natural breaks. Damage the roots below as little as possible. Remove any rhizomes that are sunken and damaged or dead.
Fill in holes left behind with soil and compost. Fill in around your existing clump with soil and quality compost, such as Black Gold Garden Compost Blend.
Pot or plant the iris divisions. Plant the rhizomes in a sunny location. Amend the garden soil with compost or peat moss, and make sure that it drains well. Plant iris rhizomes as they naturally grow–with the tops exposed to the air and light. Planting them too deeply can be deadly.
I hope that these tips help! Happy iris moving and planting.
“Why Did My Iris Take So Long to Bloom? I planted Irises about three years ago & this is the first year they have bloomed. Is that normal?” Question from Rosie of Wichita, Kansas
Answer: I am going to assume you are growing German bearded iris (Iris germanica), the most common iris variety in the United States. There are lots of factors that may have caused yours to be late in blooming, such as small starting size or less-than-ideal growing conditions. Since I am not certain of your plant’s garden conditions, let me simply share what German iris need to thrive.
These popular garden flowers perform best when given full sun and fertile, well-drained soil conditions. (I recommend adding Black Gold Garden Compost Blend if your soil is low in organic matter.) Bearded iris rhizomes should be planted with the tops at or slightly above the soil surface, as those planted too deeply may result in lush foliage but fewer or no flowers. Late spring freezes, which can halt early stem and bud development after the plant has sprouted, are another common cause for lack of flowering in bearded irises. Other factors that might have impacted the delay in blooming are lack of sufficient sunlight, poorly drained soil, or insufficient soil nutrition.
I hope that these insights help. And, if you think there are some improvements that can be made to the growing conditions of your iris, I encourage you to make them. It is always wonderful when iris are in full bloom in spring.