Cane begonias are a popular type of begonia and besides
the various species canes, there are hundreds of cane hybrids.
Cane begonias are distinguished from the other types by their bamboo
like stems. Most are free blooming and have large clusters of
flowers, many are even ever blooming. Many also have fragrance
that is most detectable in the morning hours from female flower
clusters.
There are four main types of begonias; Superba Canes,
Intermediate type Canes, Rubra type Canes, and Mallet Canes.
Previously the term angel wing was used to describe this type of
begonia but that term has been replaced by the name cane-like, or cane for short, at least
officially. (note: the terms Intermediate and Rubra type
are terms used by the author and not in common usage. Currently
those types are called All Others which the author feels doesn’t
sufficiently distinguish them) Pictured cane is Begonia 'Miss
Julie' photo by Mike Flaherty
Superba Canes
A superba is a cane that has B. aconitifolia, B. sceptrum,
or B. leathermanaie (formerly called B. plantanifolia) in its parentage
and also has deeply lobed or cleft leaves. Most have leaves that have
silver markings on them, a few are completely silver. Nearly all
are tall growing vigorous plants but they can be pruned to manageable
sizes. Representatives of this type are begonias such as B.’Irene
Nuss’ and B. ‘Sophie Cecile’.
Intermediate
Type Canes
Intermediate type canes would be all canes that fall
somewhere between the Superba type and the Rubra type. Many of
these have some superba blood but lack the deeply lobed or cleft leaves that
distinguish the Superba type. However, most are lightly lobed,
curly edged or have serrated margins to the leaf so aren’t strictly
Rubra type either. They come in a range of sizes, shapes and
silver or white markings. The markings range from spots and
splashes to some having leaves entirely white or silver. Examples
of this type are B.’Ripsaw’ and B. ‘Josephine’.
Rubra Type Canes
Rubra type canes are the most common type of canes and
have leaves that have edges with no serration or are entire. This
type of cane comes in the same range of sizes and colors as the
previous two types. Many of the older types however have plain
green or bronze leaves with no markings. This type also comes in
the full range of sizes from low growing types to ones that grow ten
feet tall if allowed to. Most are heavy blooming during the warm months of the year or
everblooming. Examples of this type are B. “Orange Rubra’ and B.
‘Tom Ment’.
Mallet
Type Canes
Mallet type canes are canes with unusual coloring or texture to the
leaves. Nearly all of them are hybrids between canes and other
begonia types such as shrubs or rexes. If the type was strictly
adhired to there would actually only be four or five begonias that
would be true mallets. These would be the original B. 'Arthur
Mallet' and it's progeny. That wouldn't be much of a
classification so I feel that all canes crossed with other types that
resemble the original mallets should be included. Actually if
they were all put into a distinctive shrub class that would be a more
appropriate placement for them. That said, nearly all
mallets have colorful leaves that are thin
textured. They also are usually sparsely hairy. A few lack
the rex like coloring but have the thin textured leaves with sparse
hairs and are also cane x B. U062 so have been included in this class.
Many of the newer mallets are hybrids between canes and
B. U062. B. U062 is a shrub with mallet coloring to the
leaves. Examples of this type are B.’Arthur Mallet’,
B.’Don
Miller’ and B.’Aya’
Cane
Culture
Potting
Canes are one of the easier types of begonias to grow and
will grow in all the different types of pots available. Plastic
pots are the most commonly used type of pots for canes. They grow
well as either hanging baskets or as potted plants. They also do
well grown in the ground. Like nearly all begonias, canes require
a well drained potting mix and resent soggy feet.
When repotting, canes should be placed as low in the new
pot as possible. This may require removing extra mix from the
bottom of the rootball to be able to have them sit lower. The
reason for potting lower is to bury more stem buds which will encourage
more basal growth and also cause more roots to form on the buried
parts.
Pruning
Unless grown indoors, where pruning can be done any time
of year, most canes should be pruned in the spring. Unless you’re
purposely trying to grow a tall specimen plant, most varieties should
be pruned fairly hard to encourage new basal shoots. Canes not
pruned have the tendency to become bare stemmed on their lower parts.
Superba types should be pruned back fairly hard in Spring, then allowed
to grow freely the rest of the year. The other types should be
cut back the same but the smaller leaved varieties benefit from
routinely pinching the tips to force side branching and fullness.
Canes routinely send up strong sturdy stems from the
roots. This growth appears almost like some sucker type growth
but this is the normal growth of the plant. On superbas, these
can be left alone. For growing in baskets, or for the other types
of canes, these stronger shoots should be pruned back as they appear,
down to the lowest outward facing bud. This will force the plant
to put out weaker side branching. This will fill in the plant and
make it conform to the rest of the plant’s growth.
Watering and Fertilizing
Canes don’t like to be overwatered. Mature plants
however are among the most tolerant of overwatering than any of the
begonia types. A well draining mix is preferred. Extremely warm
areas of the country made need a more water retentive mix though.
Canes should be watered after the mix surface has become dry.
Canes benefit from quarter strength fertilizer given weekly through out
their active growing season. Over watered canes will drop lower
leaves. Avoid getting water on the leaves of canes when they are
in direct sun or the weather is overly hot to avoid causing leaves to
burn. Under ordinary conditions getting water on the leaves
doesn’t bother most canes. Any varieties that are prone to brown
tips will be less prone to this problem if you avoid getting their
leaves wet when watering. An example is B. albo picta
which is very prone to brown tips.
Light and Heat
Cane begonias do best when given good light all
year. Most benefit from full early morning or late afternoon
sun. Filtered sun all day is preferred. There are very few
canes that will perform well in complete shade. Most won’t bloom
in low light. Canes in hot climates may burn if given late
afternoon direct sun. Most canes do well in 50% shade provided by
shade cloth in coastal areas of California. Begonias in Texas or
other hot climates may require more shade than other areas.
In frost free areas most canes will over winter outdoors
with no protection. Many canes suffer from leaf drop during
colder weather. This is normal unless caused by disease,
overwatering, or pests. Some of the more tender canes such as
B.’maculata’ and it’s hybrids, mallets, small stemmed and miniature
canes, and especially mildew prone varieties may require winter
protection. This can be provided by a temporary greenhouse or by
bringing indoors if you don’t have a greenhouse to move them to.
Even an unheated clear plastic shelter will usually be enough to carry
them through.
Canes are prone to sudden leaf drop during sudden extreme
temperature changes. Not sure of the cause, may be a genetic
feature designed to protect the plant from extremes. It is normal
but you should be aware of this problem when moving plants. It is
common for plants taken to shows to drop leaves and all their flowers
afterwards. They quickly recover when put back in their normal
growing conditions however.
Pests and
Diseases
The most common insect pests for canes are mealy bugs and
aphids. Keeping dried stipules removed from your plants will
remove most of the hiding places for mealy bugs. Yearly pruning,
as suggested above, will take away any pests so you’ll start out fresh
each year. Canes can also be prone to Prichard’s mealy bugs,
which are a type of mealy bug that lives in the soil and attacks the
roots. This pest should be suspected in any plants that decline
for no apparent reason. The root death caused by these mealy bugs
mimics overwatering type symptoms. An insecticide specifically
for root pests is required to get rid of them.
Aphids are most commonly seen on canes in the winter and
spring on the under side of new leaves. Routine inspection under
the leaves will help catch and infestation before it gets out of
hand. Any plant that puts out new leaves that are distorted or
mottled should be suspect for aphids and inspected. Nearly every
insecticide kills them. They can also just be washed off with a
strong spray of water but they usually return using that method.
Many canes are prone to powdery mildew. Superbas are
the least prone and mallets are the most prone. Varieties found
to be mildew prone have to be sprayed routinely to prevent reoccurrence
and to control. Sometimes moving them to a different location
will help them be less prone. Air circulation has very little
influence on the amount of mildew.
Canes can also be prone to bortrytis especially during
cool damp weather. This can cause stem and leaf drop.
Seeing leaves that seem to rot from the petiole is usually
bortrytis. On worse cases, a gray fuzzy mold appears on the
rotted portions. Keeping bad leaves picked up and removed will
help with prevention. There are also some fungicidal sprays that
can help control the problem.
Propagation
Nearly all canes can only be reproduced by stem cuttings
except for the species which of course can be started from seed.
Only a handful can be started from leaf cuttings and all of these are
hybrids between canes and other types such as some of the
mallets.
Special Uses and Tips
Cane begonias are very flexible and there are varieties
for nearly every specific purpose. They also respond very well to
training. If planted in the ground and allowed to grow in a semi
wild state, most will be tall large plants. Many of the superbas
and some of the others can attain eight or ten feet tall easily if
allowed to. With the exception of a couple of the more vigorous
superbas though, nearly all begonias can be kept to a small manageable
size. There are very few that can’t be confined to an eight or
ten inch pot and kept to two feet tall or less tall for many
years. Most canes can also be grown as nice full hanging baskets
with proper pinching and pruning. Some of the superbas would
require large baskets however. Canes can also be easily trained
as standards or grown on trellises. This page will be updated again soon with a pictures gallery and more info