FLOWERING PLANTS FOR HOMES AND OFFICES
Bob Anderson, Extension Horticulturist
Everyone enjoys the addition of a bright
flowering plant to their home or office. Flowers of all colors are available
for interior use and a few can be kept year after year for a continuous
or once-a-year show of color. As with all houseplants, appropriate selection
and the correct plant care will determine your satisfaction with the potted
plant you purchase.
Flowering plants are available from
plant retailers--florists, greenhouses, garden centers, supermarkets, department
stores, etc. Potted flowering plants should remain bright and colorful
for two to four weeks in the home. Some may last up to three months when
given the correct home care.
This publication discusses the most
common flowering plants and organizes them into groups that require similar
care in the home. Important points are made regarding the best conditions
for these plants in the home plus cultural techniques used to grow them
year after year.
Flowering Pot Plants
Flowering Process as a Stage of Growth
The floral display produced by a flowering
pot plant is the result of great energy input. Some of this energy comes
from the greenhouse operator as they control the greenhouse temperature,
plant nutrition, watering and pests during the growth of the plant. But
the greatest energy input is from the plant itself. Plants collect energy
from the sun for the manufacture of carbohydrates for plant growth. Development
of stems, leaves and roots consumes most of the manufactured food. The
plant must produce extra food for development of the flowers.
Flowers are the attractive portion
of plants we use for indoor or outdoor decoration. For plants, however,
flowers assure pollination and reproduction. Plants utilize much of their
energy to form flowers; their effort determines the continuation of their
kind. Because of the plant's great energy input to form flowers, it is
clear that flowering pot plants require optimum conditions indoors. They
must receive a great deal of light to support their flowers.
Flowering is a crucial time in the
life of a plant. Plants in full flower are at the end of their practical
life. Thus, flowering plants are more sensitive to cultural mistakes--overwatering,
insufficient water, high temperatures, inadequate light, etc.--than foliage
plants. The majority of plants mentioned below either must be discarded
after flowering or they require special care after flowering until the
plant produces flowers again.
Environmental Requirements of Flowering Pot Plants
Plants listed in this publication will
tolerate the environment of a typical home for two to three weeks but each
will perform best when given the conditions it requires. For long lasting
flowers in your home, follow these guidelines:
1.Place your plants in the brightest
location. Many plants enjoy full sun for two to five hours each day. These
plants require high amounts of light to produce sufficient food for the
maintenance of the flowers and foliage.
2.Water the plants regularly and thoroughly.
Be sure the pot has free drainage even if it is wrapped in decorative foil.
Fertilization is unnecessary except for those plants you hope to reflower.
3.If possible, give your plants a cool
night temperature. All plants will last longer if they receive night temperatures
of 60 degrees F; some plants prefer temperatures as low as 50 degrees F.
Plants That Flower Year Around
A number of plants can be grown to
flower year around especially if you are satisfied by their colorful foliage
while waiting for new flowers to appear. Geraniums, African violets, begonias
and impatiens were the commonly grown houseplants in this category until
recently introduced gesneriads (Gesneriaceae) and acanthids (Acanthaceae)
expanded the list of regularly flowering houseplants.
Temperatures of 65 to 75 degrees F
are best for these plants and relative humidity typical of a home or office
is usually adequate. Watering, fertilization, growing media, container
and pest control needs are similar to those of all small houseplants. Refer
to Extension Publication HO-44, Houseplants: Problems and Care, for complete
information on the care of all houseplants.
Flowering plants usually require more
light than foliage plants. To generate enough extra energy to produce flowers,
flowering plants should receive bright reflected light all day or full
sun for two to five hours each day. If any of the following plants fail
to flower, the problem is usually caused by insufficient light.
Artificial light can supply the total
light needs of these plants in the home. In fact, the gesneriads are the
best plants to grow if you must use artificial light in your home or office.
Cool white fluorescent lamps are the most economical light source for general
purpose plant growth indoors as long as they are within 18 inches of the
plants' leaves. The serious home gardener or collector may prefer specialty,
plant-growing fluorescent lamps for certain plant species. Wide spectrum
incandescent spot lights developed for plants can also be used in the home
but they are more expensive to operate and best used only to supplement
Acanthids (members of the Acanthaceae)--These
plants are grown for their long lasting, brightly colored flowers and bracts
organized into short spikes.
Brazilian Plume (Justicia carnea)
Firecracker Flower (Crossandra infundibuliformis)
Monkey Plant (Ruellia makoyana)
Shrimp Plant (Justicia brandegeana)
Yellow Lollipops (Pachystachys lutea)
Zebra Plant (Aphelandra squarrosa 'Dania') -- The zebra plant
will not tolerate excess water.
Begonia (Begonia X semperflorens-cultorum)--Many
cultivars of fibrous rooted begonias grow well indoors in a bright window.
Plants that have been grown outdoors all summer can be propagated in early
fall and brought indoors to flower during the winter.
Geranium (Pelargonium X hortorum
and P. peltatum)--Geraniums have been grown as flowering houseplants
for years. It is best to propagate new plants from your outdoor geraniums
for winter flowers indoors. Traditional cultivars will grow better indoors
than modern seed-propagated cultivars.
Gesneriads (members of the Gesneriaceae)--Gesneriads
are known for their colorful and unusual flowers that occur throughout
the year or as seasonal displays.
African Violets (Saintpaulia ionantha
cultivars) --African violets are available in all colors except yellow
and orange, and with great variations in flower form. Modern patented cultivars
have eliminated many of the problems common in the culture of the plants.
If your plants have adequate light (up to four hours of full sun), receive
small amounts of fertilizer in alternate months and are watered from the
bottom only when the growing medium is nearly dry, you will have beautiful
Cape Primrose (Streptocarpus
X hybridus cultivars)--The cape primrose has larger flowers and larger
leaves than an African violet and requires more light.
Cardinal Flower (Sinningia cardinalis)
Columnea (Columnea, numerous
species and cultivars)--Columneas are excellent basket plants.
Flame Violet (Episcia cupreata
cultivars)--Flame violets require higher humidity than other gesneriads
Goldfish Plant (Nematanthus,
numerous species and cultivars)
Lipstick Plant (Aeschynanthus pulcher)--Lipstick
plants are best in hanging baskets.
Sultana, Impatiens, Bloomin' Fool
(Impatiens wallerana cultivars )--Any of the bright sultana cultivars
will flower well indoors. Propagate plants in early fall from those grown
outdoors for winter flowers.
Plants Reflowered With In-The-Home Rest Conditions
Flowering pot plants that reflower
year after year often require a rest period. The proper rest conditions
are readily available in the home for some of these plants.
Except for the poinsettia and the Christmas
cactus, the plants of this group are native to regions of the world that
have hot, dry summers or cool, dry winters, but good growing conditions
the rest of the year. To survive the dry season, these plants have developed
a specialized stem (bulb, corm, tuber, etc.) that remains alive below the
soil surface after the flowers and leaves die. Thus, a rest period, when
the specialized stem is stored dry, is necessary for the perennial growth
of these plants in the home.
For the greatest success, try to duplicate
nature by watering the plant less frequently when flowering ceases and
the leaves turn yellow and die. Store the bulbs, corms or tubers dry for
two to four months, repot them if necessary and begin to water the plants
(gradually at first) to bring them back to life.
Poinsettias and Christmas cacti require
special conditions to initiate flowers but do not require a rest period.
cultivars) --Be sure to give your amaryllis good growing conditions after
the flowers have died so the leaves can produce food to fill the bulb for
flower formation. Store your amaryllis bulb cool (55°F) and dry in
the fall; repot the bulb only when necessary (every four to five years).
Begonia, Hanging and Rieger
(Begonia X tuberhybrida, B. X hiemalis cultivars)--Tuberous
hanging begonias are usually grown outdoors in summer while the Rieger
begonia is a common pot plant in spring, fall and winter. Begonia tubers
are stored cool (45°F) and dry during the winter, replanted in spring
and will flower all summer. Rieger begonias also require a rest period
but do not have tubers. Simply allow your Rieger begonia to dry gradually
when flowers have faded. Cut the stems to two inches from the soil, keep
the plant dry for 10 days, then gradually increase watering frequency as
new growth develops. Rieger begonias require short natural daylengths to
initiate flowers so plants usually flower in late fall and winter.
Holiday Cactus, Christmas Cactus,
Thanksgiving Cactus (Schlumbergera bridgesii, S. truncata
cultivars)-Christmas cactus and related cactus plants should be grown as
foliage plants from January to September with regular watering and fertilization.
Reduce watering by one-half in September and keep plants outdoors until
mid to late October while protecting them from frost. Cool night temperatures
during early fall in Kentucky should cause flower initiation. If plants
cannot be kept outdoors, they will require natural or shortened daylengths
for flower initiation (see Poinsettia).
Cyclamen (Cyclamen persicum
cultivars)--Warm temperatures and drought decrease the life of cyclamen
in the home. When plants cease flowering, gradually decrease watering until
leaves die. Store the corm cool and dry for one to two months, repot into
peat moss growing media and grow the plant in a cool, partially shaded,
Gloxinia (Sinningia speciosa
cultivars)--Allow the plants to dry slowly after flowering is completed.
Store the dry gloxinia tubers for two to four months. Repot and water the
plants as new shoots develop on the tubers. Gloxinias require a bright
location, but not full sun, for best growth.
Lucky Clover, Shamrock (Oxalis
deppei, O. purpurea)--These small clover-like plants with white
or pink flowers will have yellow leaves and poor growth when they need
their rest period. Simply allow the plants to dry gradually, store the
bulbs in their pots for one to three months and begin watering the pot
when you want the plants to develop again.
Poinsettia (Euphorbia pulcherrima
cultivars)--Spring and summer growth and the correct daylength in October
will determine your success in reflowering a poinsettia. Plants should
be grown vigorously in full sunlight (indoors or outdoors) with regular
watering and fertilization during spring and summer. Prune plants regularly
to maintain the size and shape you prefer but do not prune after September
10. Plants must receive uninterrupted natural nights or 14 hours of darkness
each night from October 1 to November 5 in order to produce flowers for
Christmas. Place plants in a closet or beneath a light-tight box at 6 p.m.
each night and bring plants to their normal full sun location at 8 a.m.
each morning. Never permit artificial light from any source to interrupt
the night period.
Plants Reflowered With Special Rest Conditions
A number of flowering pot plants, while
prized for their outstanding floral display, require special rest conditions
of 35 to 50°F to assure annual flowering. Since the cool rest period
must be consistent throughout the winter, the best place to grow these
plants is in a cool greenhouse, hot bed or glass-enclosed porch with appropriate
heating and ventilation equipment. Plants flower quickly and deteriorate
rapidly when brought into a warm (70 degree F) environment after their
6- to 10-week rest period, so a home gardener also needs a cool area (50
to 55 degrees F) where these plants can be slowly forced into flower.
These plants are grown as flowering
shrubs in southern landscapes and most are not hardy in Kentucky or northern
Azalea (Rhododendron Indicum
hybrids)--Azaleas are available from plant retailers year around, but primarily
from Thanksgiving through Easter. These plants require an acid peat growing
medium and a shaded summer location for continued growth.
Camellia (Camellia japonica
cultivars)--Camellias must remain in a cool area (50 to 55°F) throughout
the winter as they flower. Any sudden change in temperature, watering,
humidity or location in a room may cause flower buds and leaves to drop.
There is no way to remedy this problem except to wait for flowers next
winter. Like azaleas, these plants require an acid peat growing medium
and must be kept shaded in summer.
Heath, Heather (Erica,
various species)--A common pot plant in Europe that is sometimes grown
in the U.S. for its display of small white, salmon or pink flowers. Overwinter
at 40 to 45°F and keep plants in acid peat growing media.
Fuchsia (Fuchsia X hybrida
cultivars)--Fuchsias are commonly sold for Mother's Day in Kentucky. Plants
should be kept outdoors on the patio in the spring because they deteriorate
rapidly indoors during hot weather.
Gardenia, Everblooming (Gardenia
jasminoides 'Veitchii')--Many home gardeners have good luck growing
gardenias year around in Kentucky. These plants enjoy a cool location (60
to 65°F) with bright indirect light during flowering in winter and
a shaded spot outdoors in summer (must be brought indoors before the first
frost). Gardenias are available throughout the winter and spring but most
people find the plants are temperamental and sensitive to watering, temperature
and humidity changes. Iron chlorosis is also a very common problem when
Hydrangea (Hydrangea macrophylla
cultivars)--Hydrangeas are hardy in Kentucky and are probably best used
as a flowering landscape plant. They can be forced for spring flowers year
after year but this will weaken the plant, producing smaller flowers.
Flower buds develop during the cool
fall weather. If you wish to force your hydrangea, decrease water and fertilizer
applications as leaves deteriorate and fall. Plants need six to eight weeks
of cool storage (40 to 45°F) in the dark before flowers can be forced
in a full sun location at 50 to 55°F. Pink flowers are obtained when
plants are forced in a neutral growing medium; add hydrated limestone (agricultural
lime) (2 tsp. per pint of water) to the plant in four to six applications
at two-week intervals until flowers begin to open. For blue flowers use
similar applications of aluminum sulfate (1 to 1-1/2 tsp. per pint of water)
to acidify the growing medium.
Rose, Baby or Polyantha (Rosa
multiflora, R. X rehderana cultivars) --Miniature roses are
forced for Mother's Day and late spring sales. Many of these roses are
not winter hardy in Kentucky and require a cool rest period in a uniform
environment for reflowering.
Plants Difficult to Reflower and Usually Discarded
Unfortunately, many flowering pot plants
are discarded after the flowers have deteriorated. Some of the plants could
be reflowered but the cultural conditions necessary would be difficult
for a home gardener to master. A number of the plants are annuals and simply
die after flowering. Others are bulbs that are forced to flower out-of-season;
these plants have been weakened by the forcing conditions. They might die
or would not form flowers until one or two normal growing seasons have
Bellflower (Campanula isophylla)
--A small plant with many blue bell-shaped flowers that is available year
around and great for hanging baskets.
Christmas Cherry, Jerusalem Cherry
(Solanum pseudocapsicum) --A common Christmas plant with tomato-like
red fruit. This plant is being displaced by the Christmas peppers because
they are easier to grow.
Christmas Pepper, Ornamental Pepper
(Capsicum annuum cultivars) --Plants with bright red, yellow,
or purple fruits commonly available for Christmas and in small pots during
Chrysanthemum, Mum (Chrysanthemum
X morifolium cultivars)-Potted chrysanthemum plants are extremely difficult
to reflower. The plants may not be winter hardy in Kentucky if planted
outdoors. Mums require intensive cultural techniques (growth regulators,
photoperiodic treatments, etc.) to produce a plant similar to the one originally
purchased. Garden mums purchased in flower during spring and summer can
be planted outdoors in Kentucky and are often hardy.
Cineraria (Senecio X hybridus
cultivars)--This cool season annual flower cannot be reflowered but can
produce an outstanding show indoors or in patio containers outdoors in
the spring. Beware--this plant wilts very easily indoors.
Crocus (Crocus cultivars)--These
small inexpensive bulbs can be forced after a cool temperature treatment
and used indoors in cool locations. When flowering is completed, potted
crocuses can be removed from their pot and planted outdoors for next year's
Daffodil or Jonquil, Paperwhite
(Narcissus pseudonarcissus cultivars, N. tazetta)--Daffodil
bulbs can be forced for indoor use after a cool temperature treatment.
Plant daffodil bulbs outdoors when flowering ceases. Daffodils naturalize
readily in Kentucky. Paperwhite bulbs can be forced without a cool temperature
treatment by placing the bulbs in low, pebble-filled, drainless containers.
Plants flower in approximately two months if grown in a cool, full sun
location when the water level in the container is kept just below the base
of the bulbs.
Dahlia (Dahlia cultivars)--A
very attractive spring flowering pot plant is produced by forcing dahlia
tubers with recently developed cultural techniques. Plants moved to your
garden in early summer will develop into typical garden dahlias.
Easter Lily (Lilium longiflorum
cultivars)--Easter lily bulbs cannot be forced to flower again, but can
be planted outdoors because they are winter hardy in Kentucky. Plant the
whole plant outdoors in late spring. Leave the foliage on the plant until
it turns yellow and dies; this signals that the bulb is prepared to flower
Exacum (Exacum affine)--A
small pot plant that is produced year around for its small blue flowers.
Hyacinth (Hyacinth orientalis)--Hyacinth
bulbs require a cool temperature treatment before forcing for indoor use.
Kalanchoe (Kalanchoe blossfeldiana
cultivars)--New cultivars with longlasting flowers are more difficult to
bring into vegetative growth after flowering has ceased and plants have
been pruned. Plants may flower in winter only if they receive uninterrupted
natural daylengths in the fall (see Poinsettia). Remember this is a succulent
plant that requires less water than most flowering pot plants.
Pocketbook Plant (Calceolaria
crenatiflora cultivars)--This cool season annual flower cannot be reflowered
but can produce an outstanding show in a cool, indoor location or outdoors
in patio containers in the spring.
Primrose, Primula (Primula
X polyantha, P. malacoides, and others)--These plants are probably
best outdoors during the cool temperatures of spring, but their distinct,
bright flowers of many colors encourage home gardeners to bring them indoors.
Tulip (Tulipa cultivars)--Tulip
bulbs can be forced for interior use only after plants have received cool