University of Vermont Extension
Department of Plant and Soil Science
EASY HOUSEPLANTS-- BEGONIAS
Dr. Leonard Perry,
University of Vermont
are an easy houseplant for beginners, with a range of species and
for the more advanced gardeners. Some
are grown for flowers, others for their foliage. They come in a
range of sizes, shapes, and
habit, from upright to spreading. Many
tolerate low light, and they have few if any pests.
deal first with the main need for begonias indoors, especially in
with forced air heat, that being to increase humidity levels around
plants. You can keep a misting bottle
(as found in hardware or home stores) nearby and mist plants daily.
If this will harm walls or furniture, try a
humidifier (this will help the air for you as well). Placing plants
on a tray of pebbles, and
keeping this moist by watering the pebbles every day or two helps.
If plants are under lights, or some form of
plant stand, you can place plastic over and around this to maintain
humidity within the “tent.” Many
begonias will tolerate some dry air, but won’t thrive.
plants watered, but not too wet. If in
doubt, don’t water. Let soil dry between
watering, then water thoroughly so water drains out the bottom of
pots. But don’t let plants sit in a saucer of
water. You can place water in a saucer
under pots, letting the soil wick-up and absorb the water, just make
drain any left after an hour or two.
soil mix is best for begonias? Use a
soil-less mix, one formulated just for indoor plants and usually
peat moss and perlite or vermiculite.
Don’t use amendments as you would in the garden, such as compost,
garden soil. These may be good in the
garden but behave quite differently in pots, keeping plants too wet
don’t like too large of a pot, preferring to be pot bound. If you
have a plant that takes days to dry
out, perhaps the pot is too big and you should repot into a smaller
pot. If pots are too large, the mix remains wet
for too long and often leads to root diseases.
fertilizer (according to label directions on product of your choice)
plants are growing. This actually might
be in winter when leaves are off trees and more light may come in
windows or be
reflected off snow outside. Perhaps
better when fertilizing is to use a product at reduced strength, but
like it warm, not being happy below about 55 degrees (F). More
ideal are temperatures between 62 and 72
degrees, with some difference between day and night.
preference varies with the type of begonia, so look for this on
catalogs, online, books, or ask your garden retailer for advice.
You usually won’t go wrong using bright
natural light, but little direct sun (such as an east window) or
(as with sheer window drapes). Too much
direct sun can “burn” leaves, causing discoloration or browning.
for most begonias is a supplemental light stand, which could be as
inexpensive shop lights with fluorescent tubes.
Suspend these over plants, a few inches between the tops of plants
light tubes. Or you can use directed
spot fixtures with full-spectrum light bulbs, if possible. Keep any
lights on for about 14 hours a day,
or in the evening to supplement daylight from windows during short
winter days. Inexpensive timers from hardware or home
stores work well for controlling lights.
end up with leaves staying too wet, as in a tented structure, a
called “powdery mildew” may cover leaf surfaces. Keep the plants
drier and this should
disappear. While begonias get few if any
pests, keep an eye out for small white cottony masses, particularly
leaves join stems. These “mealybugs” are
easily controlled by dabbing them with rubbing alcohol.
begonias get too tall and leggy, you can root cuttings for more or
plants. Or just cut (“pinch”) plants
back to the desired height, from which point they’ll grow
sideshoots. If rooting cuttings, place in a mix of sand
and peat moss, or perlite, keep moist, and keep humid as in a clear
over the pot (but check daily to make sure plants are too wet). Too
tall and leggy may indicate too low light
or too much fertility, or old plants needing rejuvenation.
begonia family is huge, with over 1,600 species and thousands of
selections. Some are grouped by root type. Those growing from a
swollen yet flattened,
brown tuber structure-- the tuberous begonias-- are best grown
summer in shade. Those from an enlarged
underground stem or rhizome, or those with fine fibrous roots,
well indoors. While the former are
usually grown for their leaves and tolerate lower light conditions,
are usually flowering species for bright light.
see begonias grouped by habit, such as spreading, shrub,
thick-stemmed, or cane
types. Some recommend the shrub and cane types as better choices for
shrub begonias have multiple canes from the base to make a rounded
plant. Cane begonias have tough jointed stems (think
of bamboo canes). Another simple
grouping consists of the flowering types, and those grown for the
foliage begonias, the most common are the Rex begonias with their
perhaps 6 inches wide, in various shapes, and even more striking
including reds, silver, green, pink, purple, and gray. These are
usually rhizomatous, and often need
more humidity and moisture than other begonias. All the variations
descend from one ancestor, a species native to the northeastern
Indian state of
flowering types, the most common may be the fibrous-rooted wax-leaf
called semperflorens from the species name), and cane-type angel
begonias. The names are descriptive of
their leaves, and their small flowers come in various colors of
reds, pink, and
white. These are
often the types you see and use in summer gardens, and which can be
before frost in fall and brought indoors.
begonias are another flowering type, being semi-tuberous and
developed for long flowering indoors. Angel
wing have winged-shaped leaves, often with white or silver
markings. These two types, the angel wing and wax-leaf,
have been crossed to make the Dragon Wing begonia. They have the
leaf shape of angel wing, but
are green with no markings.
rather new and popular type, with solid green angel-shaped wings, is
Bolivian begonia, found growing naturally on the cliffs of
Argentina. These are great in hanging baskets or pots,
reaching up to 2-feet across and covered in flowers all summer.
Popular examples are the bright orange
Bonfire and scarlet red 'Santa Cruz Sunset'.
want to see some of the range of indoor begonias, make plans to
greenhouses at the Montreal Botanical Gardens
(espacepourlavie.ca/en/botanical-garden) where they have one of the
collections in North America. Or you can
find more resources, with photos, from the American Begonia Society