47 (June 1980, pages 156 - 157)
Easy to grow: fragrant B. solananthera
by Elda Haring
Grown as easily as philodendron or ivy, B.
solananthera is one of my favorite begonias. In late winter and early
spring, the flowers are so fragrant they fill the whole greenhouse with
perfume much like that of orange blossoms.
This begonia was found in the wild in Brazil as long
ago as 1859. It is classified as trailing and scandent (climbing). The
heart-shaped green leaves are about two inches in length on trailing
The heavy clusters of white flowers dangle from the
leaf axils covering the plant. The centers of the flowers are red, hence
the common name of "Brazilian heart." As both male and female flowers are
open at the same time, this plant can be self-pollinated easily to produce
seed for the Seed Fund or to be shared with your friends.
When I first obtained my plant years ago, I had no
room for hanging baskets and I grew it in a deep pot, raising it above the
bench by placing it on an upturned pot. On the windowsill or under
fluorescent lights, the pot is kept in a footed compote so the stems do
not rest on tray or table.
As with cane-like begonias, the new leaf grown at the
tip of each branch is pointed. Pinching out this unfurled new leaf
encourages the plant to branch and fill in at the top of the pot or
basket. This practice may be continued until the stems are long enough to
B. solananthera likes good light but needs to
be protected from too much sun unless the sun in winter where you live is
very weak. It thrives in the shaded greenhouse or window during summer.
This begonia I have found grows happily in a variety
of potting mixes as well as in any of the soilless mixes. As I use soil,
sand, peat, dolomite, and bone meal in my potting mixes, I do not add
additional fertilizer until the plant has become well established. At that
time, I begin fertilizing twice a month through the growing season with
one of the water-soluble fertilizers like Miracle Gro, Ra-Pid Gro or Plant
Marvel. During winter, it gets an occasional feeding of six drops of
Schultz Instant to a quart of water. If you use a soilless mix, constant
feeding is needed.
If the root ball of B. solananthera becomes
dry, the leaves will turn pale and assume a glassy appearance. This is
your cue to give it a thorough soaking, then not to water again until the
top of the mix feels dry. The plant needs be only very slightly moist
during the chilly and dark days of winter. If the temperature in your
plant room or greenhouse is low, too much water will cause rot. Plant food
cannot be assimilated by roots of plants if the potting mix is very cold.
The time to take cuttings is immediately after
flowering no later than early autumn. I like to place four or five
cuttings close together, back-to back, in a 4-inch pot of propagating mix
with leaves pointing outward. When a firm tug indicates roots have
developed, feed half-strength fertilizer once a week until the pot is
filled with roots. Then the entire mass may be removed and placed in a 6-
or 8-inch basket or in a 6-inch pot.
I use plastic baskets with attached saucers in my
greenhouse because I do not want water dripping on the plants on the
bench. My friends Mildred and Edward Thompson prefer wire baskets lined
with sheet moss.
Under fluorescent lights or in windows, it is best to
grow B. solananthera in either plastic or clay pots placed inside
decorative footed containers with a layer of gravel in the bottom. When
growing plants this way, be sure to check frequently to be sure no water
reaches the bottom of the pots for the roots of the plants rot if the pot
is standing in water.
Keep in mind that this delightful species blooms in
winter, indicating it needs a short day to initiate flower buds. If grown
in a window, it should be kept in a little-used room where no lights are
burning at night. When buds have developed, it may be brought into the
dining or living room to be enjoyed.
If you are growing under lights, reduce the time the
lights are burning to 10 hours beginning in late November.
After the buds have been set, the lights may be timed
to burn 12 to 15 hours a day.
One of the most fragrant
begonias, B. solananthera. Photo / Walter Haring.
This article was reprinted in the Cascade Branch
Newsletter, December 16, 1997.