How to Transplant Siberian Iris

Unlike their taller cousins, the bearded (or German) irises, Siberian irises stand only 10 to 34 inches tall at maturity. Their foliage is fine and grasslike, and their flowers are compact and generally upright, though some varieties do have lower petals (falls) that droop slightly. Don't let their dainty looks fool you, however---these irises are tough little customers, easily grown in virtually any climate zone, in full sun to partial shade. Siberian irises don't have to be divided and transplanted very often, but if your iris bed is beginning to look crowded, or if after several successful seasons the number of flowers you're seeing has diminished, it's time to dig them up and move some of them to another spot. Dig up, divide and transplant your irises in the spring, right after they have quit blooming and the foliage has started to turn brown and die back.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Shovel or hand spade
• Spray bottle full of water or a hose with a hand-watering nozzle on it
• Nitrogen-high fertilizer
• Balanced fertilizer

1. Carefully dig up each clump of iris rhizomes. Cut the foliage on the tops back to about two inches above the top of each iris rhizome.

2. Set the rhizomes aside and spray them lightly but well with a spray bottle full of water or a garden hose with the nozzle turned to mist. Spray them again from time to time until you get them transplanted--it's imperative that you keep the roots damp at all times.

3. Look carefully at the rhizomes you have dug up. You will see that new rhizomes are growing on the outside of the main rhizome.

4. Very carefully cut the rhizomes apart with a sharp knife at the junctures where the new, smaller rhizomes have started growing from the large one, being sure that each rhizome has some roots at its bottom and some fans of foliage at its top.

5. Prepare the soil in the flower bed where you intend to transplant the Siberian irises by digging it up to a depth of about six inches and mixing in enough compost or peat moss to result in a loose, rich soil.

6. Mix in a fertilizer that is high in nitrogen. Ask your local nursery personnel to recommend one for your irises and follow the directions on the package to find out how much you should use and how to mix it into your soil.

7. Smooth the soil out evenly, but do not pack it down.

8. Dig holes for your iris rhizomes that are about an inch deep and 18 to 24 inches apart. Water the flower bed lightly, so that the soil is damp to the touch of your fingertips but not soaking wet.

9. Put the rhizomes into the holes and cover them up with a scant one to two inches of soil. If you'd like more visual punch, plant three to five rhizomes together in each hole; expand the spacing between each group of plants to 24 inches apart.

10. The next day, check the soil for moisture by sticking your fingers into it close to one of your iris rhizomes. If it's not damp to the touch, water the irises again.

11. Continue to water the irises as needed to keep the soil damp, not soaking wet--at least once a week. During the spring and their blooming season, keep watering them as directed. Once irises have bloomed and the foliage has died back (usually in the summer), they can tolerate dry conditions, but while they're preparing to bloom and blooming, they need regular infusions of water.

12. After the irises have stopped blooming, apply a balanced fertilizer to encourage them to grow new rhizomes and fans. Again, consult your local nursery workers for the type you should use and apply it carefully according to the instructions on the package.

References

• Iris hybrid (Siberian); Plant Finder; Sunset Magazine
• Growing Siberian Irises; Canadian Iris Society
• Growing Siberian Irises in the Home Garden; Iowa State University Extension