Plant Or Divide Iris In August

11Iris have been called the poor man’s orchid. Because they’re so beautiful, I think I’ll opt to be a poor man. Iris have come a long way in the past 50 years, and the small-flowered less-showy varieties of yesteryear have been replaced by the gigantic blossoms and intense colors of today’s hybrids.

Most iris varieties bloom in June. August and early September are the best times to plant new iris, or dig and divide established plantings. To keep iris vigorous and full-flowering, divide and reset every 3 to 5 years. It’s not difficult and iris are well worth a little labor every few years.

Iris should be divided and replanted if flowering becomes diminished, or if the center of the clump is old and woody with all vigorous growth on the outer perimeter of the clump.

Here’s the process:

  1. With spading fork or shovel, dig clumps of rhizomes (iris aren’t bulbs like lilies or onions, but rather fleshy stem tissue called rhizomes).
  2. Separate the plump, leaf-containing rhizomes from the old central woody rhizomes.
  3. Each division should contain at least one “fan” of leaves. Cut leaves back to 4-6 inches above the rhizome. Variety names can be written directly onto leaves with a Sharpie permanent marker.
  4. Replant by fanning out the fibrous roots over a small mound of soil, with fleshy rhizome sitting atop the mound.
  5. Space plants 12 to 18 inches apart. Groupings of the same color create impact.
  6. Cover fibrous roots with soil. The fleshy rhizome should be just barely covered with soil, or slightly visible at soil level. Planting iris too deeply can cause rot and decreased flowering. Much better to err on the shallow side.
  7. Water well after planting.
  8. Label with variety name. Keeping track of variety is very important. The name of the variety unlocks information which might be needed for future questions or care concerns. Gifting iris rhizomes to others is much more valuable if you are able to provide the variety name.

Happy Gardening!

'Daring Deception' Iris
‘Daring Deception’ Iris