Hortiscope: Kalanches need some tough love, sunlight to thrive
Q: Outside an east window, I have a bush growing that I believe is a hydrangea, although I have always called it a snowball. It does bloom whether or not I cut it back in the fall, but the blossoms are very small.
Last fall, I cut it back and this year there are only two tiny blooms, unlike those of my neighbors. Of greater concern is the fact that the bush has spread out, devouring some peony plants that always do well in that location.
Would it be OK to offer these suckers to anyone who wants to dig them up but leave the original plant? If so, when is the proper time to do so? Does cutting it back in the fall increase the chances for it to spread?
A: The best time is when it is dormant. Do it this fall after the leaves drop or early next spring just before the leaves open. Cutting back in the fall or spring makes little difference to the character of the spread. You eventually may want to give up on these characters and grow something that is showy and nonsuckering.
Q: I have a kalanchoe plant that has been growing out of control for years. I've taken cuttings from it and started other plants, but the stems are limp and don't stand up. I've tied them to skewers to get them to stay upright. Also, what do I give them to make them bloom? They haven't bloomed since I had the first plant. Any help would be appreciated.
A: You must be referring to the kalanchoe blossfeldiana, not the K. tomentosa or K. beharensis that are known for their striking foliage but not flowers.
The flowering plant needs more light to be stronger and more self-supporting. If you cannot provide enough natural light from southern or southwestern windows, then I suggest getting a plant light and run it on 12- hour cycles. Also, stop being so nice to it. It sounds like it is getting an abundance of nitrogen based fertilizer.
Back off on the fertilization and let it go hungry for a while. That usually brings it into bloom. Create slightly tough conditions for the plant by withholding water occasionally, no more fertilization and more light duration and intensity. These will contribute to bringing the plant around to set flower buds.
To contact Ron Smith for answers to your questions, write to Ron Smith, NDSU Department of Plant Sciences, Dept. 7670, Box 6050, Fargo, ND 58108-6050 or e-mail firstname.lastname@example.org.