Skip to main content

August is the ideal time for plant divisions

Know It and Grow It
Lead Summary
George Bonnema, Luverne Horticulturalist

Marvelous rain this weekend, and I am so very grateful! I’ve been able to water enough to keep my gardens producing quality produce, but that seems such a futile effort considering the size of the gardens coupled with heat … rain changes the whole picture!
It is August, and if you have fern leaf peonies, you’ll notice they are turning yellow because they have finished their growing cycle for the season. That means if you want to divide them or move them to a different location, this is the time to tackle that project.
Dig the entire clump and wash the soil off the tuber mass so you can see what you are doing to separate them. You will notice the pink-colored eyes for next year’s growth on the stem above the tuber, and every division needs at least one but preferably three of those eyes. The tubers tend to grow as a tangled mass, but with the soil washed away they can be separated fairly easily.
When you get to replanting, be sure that eye is within one inch of the soil surface. If planted too deep, they absolutely will not bloom. Also, plant them in an area that gets sun for most of the day.
Last week I encouraged you to cut the spent flower stems out of the re-blooming daylilies.
If you daylilies have not been blooming well, it is because they are not getting enough direct sun or the clumps have become root-bound in which case they need to be divided. Now is a good time to do that. It seems that if they have been left to their own for five to six years or more, the blooming capacity is diminished by at least half.
Dig the entire clump, and using your spade, cut the clump into at least four sections and replant one of those sections back in the same spot. Water well to settle the soil around the root mass and you’re good to go.
Depending on how long they have been ignored, it may take a couple of years for them to regain their best bloom capacity.
August is also the time to divide or move German bearded iris. When you dig the rhizomes, the end with the leaves indicates the direction it will grow. Clean off any dead or dying leaves and cut the remaining leaves to an 8” tall fan. Replant, making sure the rhizome sits at soil level. It cannot be covered with soil. Again, water well to settle soil around the roots.
This summer has been brutal for our annual flowers in pots or hanging baskets. Be faithful with watering and feeding, and as the temperatures moderate, the plants will respond with renewed vigor and give a great show before frost ends the season.