Growing Concerns 609: African Violet, stall dahlia tubers

Late Winter!

Flowerless African violet may need a new pot

Dear Janet,

I have a beautiful African violet and it blooms away. Now it has stopped blooming, but continues to grow. Is my pot too small and if I transplant it will it continue to grow? I hate to try without knowing if that is right, to transplant it. I'd hate for it to die.


Dear N.C.,

I asked Ingrid Bowman of the Violet Society what you might do. "Lots of African violets get suckers -- new little plants growing up from the base. You have to pinch those off. You can pot the suckers separately and they'll grow but if you leave them, the original plant can get too crowded to bloom. Also, if it's been a very long time in the same pot, it might need to be repotted. We repot our violets more often, every six months, because we have them under grow lights and keep them growing very rapidly."

Bowman described other problems that can make an African violet stop blooming, including overwatering and a dead gray center indicating crown rot. Since you didn't indicate any such symptoms, just good growth without bloom, she came back to pinching off suckers and, "increasing the amount of light the plant receives. Give it as much sun as possible, short of direct south sun, which can burn the foliage."

You probably shouldn't worry about the plant dying. It doesn't need to flower to be healthy. Assume it is in good health if it continues to grow and does not show signs of trouble such as new leaves dying. Do expect an old leaf to gradually yellow and die from time to time. Older leaves are those around the bottom edge of the rosette.


Dear Janet,

I saved dahlia tubers from last year and thought to check them just the other day. They've started to sprout. What do I do?


Dear B.L.,

You can stall their growth by putting them in a place that's cooler -- such as the refrigerator. Or you can pot them. 

The trouble with potting them now is having to accommodate those potted plants indoors for almost three months. You'll need grow lights. Even if you put them in the sunniest place you have, the light may be too weak so the growth will be spindly.

To start dahlias indoors but delay as long as possible their need for a place in the light, I do this: Put just a thin layer of soilless potting mix at the bottom of a deep pot. Set a tuber on that and barely cover it with soilless potting mix. Moisten it and put the pot in a warm place. It doesn't need light yet.

When the dahlia's shoot shows above the surface, add another thin layer of potting mix. Keep burying the emerging shoot until the pot is full of potting mix. Then move it into full sun or put it under lights until early June.

Don't expect much bloom from a dahlia until August. Then, if you've kept the plant well watered and fertilized, it should bloom heavily until frost.


I enjoy answering questions you mail to me or post on my school's website. However, some problems have no solution. Don't expect much help from me if you pose a "stumper" such as: How come my kids didn't catch the gardening bug when they were young, when I could have made them happy with a plastic shovel and a packet of sunflower seeds? Why did they only get the urge to garden when they got their own home, a place in need of expensive trees and shrubs?


Green thumbs up

to the gardeners who are creating large, slightly sunken beds to collect run-off from roofs and paved areas. These beds of moisture-loving perennials and small shrubs are places where water can slow and settle, rather than run straight and dirt-laden into storm drains. In these "rain gardens" water is used by the plants or seeps down to replenish groundwater reserves. It's better filtration than water can get in our overtaxed stormwater treatment system.


Green thumbs down

to using "pine tree" as a generic term, lumping spruce, pine, fir and hemlock into one category. The roots, density of the foliage, growth cycles and chemical interactions are different for each tree species. This year, clip a twig with needles, leaves or leaf buds from each of your unknown trees and shrubs. Go to an MSU Extension office or garden center for help identifying them. Then you'll grow them better and garden better around them.

Originally published 3/12/05