43 (February 1976, pages 485 - 488)
Training Plants in the Way They Should Go
by Elda Haring
While some begonias are naturally
compact and low growing, many others need special handling to attain
a symmetrical plant or to keep the plants from becoming lanky,
sparsely foliaged and unattractive. If you start your training
program with young plants obtained from a commercial grower or grown
from your own cuttings, timely pinching, pruning and patience are
the essentials to develop a compact plant. If, with an eye to flower
show competition you have purchased or fall heir to a specimen-sized
begonia, some judicious pinching or pruning will produce an
attractive and show-worthy plant.
Pinch the growing tip at the end of new shoots
to stop new growth and encourage branching. You will note in the
photo of B. 'Marjorie Daw' a definite pointed tip. If left alone a
new leaf unfurls from this tip and the plant continues its upward or
outward growth. The new leaf may also be removed after it has
unfurled if done carefully, for in many cases the flowers are
produced at the tend of the branches or in the axils of the leaves
and might inadvertently be removed. You will notice in the photo of
B. 'Catalina' a new leaf being carefully removed leaving the flower
buds intact. Pinching the ends of resultant new shoots and branches
as they grow can be continued until the plant has reached the size
and shape you want. The aim is for compact, bushy plants eventually
covered with flowers.
B. 'Marjorie Daw'. Note pointed
B. 'Catalina'. Pinch
new leaf behind flower.
If the tip is removed from cane begonias while
still small, new stems will soon grow from the soil level. The
growing tips of rhizomatous begonias can be pinched out to encourage
compact growth. Removing the top inch of B. semperflorens
will force side branches, delaying flowering only slightly. While
some of the shrub-like and thick-stemmed begonias naturally grow in
a compact fashion many of them need to be pinched while young and
growing vigorously to keep them within bounds.
Pruning is practiced on old overgrown plants or
those that have become ungainly and need shaping. In the case of
begonias that have lost some or all of their lower leaves like that
of B. serratipetala in the photo, cutting all branches off
close to the pot level will cause the plant to send up new shoots.
If these in turn have the soft growing tips pinched a well-shaped
will result. If you have a cane begonia that has developed
only one stem and is much too tall for its pot, cut the cane to
within 10 or 12 inches of the pot. This will cause the plant to send
up new stems from the pot level to give you an attractive plant.
Upright rhizomes or stems of shrub -like begonias can be pruned by
cutting off protruding stems just above bushy growth to produce a
more compact and shapely plant. B. manicata aureo-maculata
shown in the photograph would have been much improved by the timely
removal of the two uppermost stems.
B. serratipetala. Cut leggy
growth to force new shoots.
Uneven growth can be avoided by early
To rejuvenate old plants it is not only possible
but most important to take drastic action. It will be
necessary to cut back many of the mature stems as shown in the photo
of B. 'Medora' to induce new growth. Remove with knife or scissors
crowded shoots or any that have become hard and woody, and shorten
the newer growth considerably to provide a suitable frame work for
the rejuvenate plant. Unfortunately there is often great reluctance
even among experienced hobbyists to cut back an overgrown begonia
for fear of losing potential flowers. Surely it is desirable to
sacrifice one season of bloom to develop a beautiful specimen
|B. 'Medora'. Cut back long
shoots after flowering is complete
||B. pustulata argentae. Trim
off long narrow rhizomes.
Recently I gave a drastic pruning to a very old
plant of B. 'Maphil'. The pot was overflowing with dangling rhizomes
and the old rhizomes were covering those at the crown. All the
rhizomes were cut off, leaving only those at the crown, and fresh
soil filled in around those remaining. Our readers may be interested
to know that the plant of B. 'Maphil' pictured has been in the same
pot for 7 years and has been subjected to this drastic pruning three
times. The old rhizomes shown in the photo when placed in a bowl of
water produced roots within two weeks and the old plant started to
show new leaves within three weeks.
|B. 'Maphil'. Start by
cutting off dangling rhizomes.
|B. 'Maphil'. Plant is
denuded of all rhizomes that were above pot
Drastic pruning is also desirable if your plants
have been badly damaged by mildew or have become extremely unsightly
whether due to insect damage or damage by rain, hail or some other
aspect of the weather. Do not discard such plants but cut them back
to within 4 to 6 inches of the pot level and treat with insecticide
and fungicide. They will recover and become more beautiful than
ever. It has been my experience that some varieties that normally
rest in winter and being grown in a cool room or greenhouse may not
begin to show new growth until spring, if such drastic pruning is
done in the fall or early part of winter.
Photos by Walter