HO-51 
FLOWERING PLANTS FOR HOMES AND OFFICES
ISSUED: 2-83
REVISED:
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 natural daylight.
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 African violets.
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 listed here.
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.
Amaryllis (Hippeastrum 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, summer location.
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 states.
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 growing gardenias.
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 passed.
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 spring.
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 flowers.
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 next year.
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 temperature treatment.