Tuberous Begonia's

Asked June 12, 2018, 11:09 AM EDT

My begonias are nice and leafed out from last year wintering them over in peat moss but don't have any flowers setting on. It's middle of june and wondering what to use for flowers. Planted them in Black Gold potting soil with fertilizer and some peat moss.

Polk County Oregon

1 Response

If you received the begonias in bloom last year, they were likely “forced” in a greenhouse where they received optimal temperatures, light, water, and fertilizer.

It‘s true that the tubers can be kept over the winter in a frost-free place. When removed from storage the following year, they need to be in prime condition, not shriveled or shrunken; if not, they won’t do as well as hoped.

Then, too, successful flowering in subsequent years depends upon other factors:

- When you start the tubers. Earlier rather than later.

- Light – Morning sunlight with bright shade in the afternoon

- Potting up: Set the tuber with the concave side up, rounded side down. Add potting mix to cover, with a maximum of 2 inches.

- Fertilizer: Begin fertilizing when the greenery is 3 inches tall.

- - - Some articles are quite specific about the fertilizer ratio, but just about any dissolve-in-water fertilizer for containers will do if applied according to label directions through the growing season; stop in the fall when flowering slows.

- - - Many labels say to fertilize once a month but you may cut the dose in half and add every 2 weeks; or cut the dose in fourths and add every week. (It all depends upon how much time you have.)

- - - If your potting mix came with fertilizer added, know that it’s only a basic dose for maintenance. You must apply additional fertilizer on a regular schedule for vigorous flowering plants.