ALABAMA A&M AND AUBURN UNIVERSITIES Greenhouse Production ANR-1258 of Gloxinias

History The species from which Florists Gloxinias were derived came from Brazil in 1785. The name Gloxinia speciosa was origi- nally assigned in 1817 by Conrad Loddiges, an English nursery- man, in honor of P.B. Gloxin of Strasburg, Germany. In 1825, the species was renamed, placing it in the correct genus, Sinningia. The original species had slipper or nodding flowers, but by the mid- 1800s, an erect, bell-shaped flower appeared. The modern gloxinia is a hybrid from two Brazilian tropi- cal species; Sinningia speciosa and Sinningia maxima. It arose as a chance seedling raised by a Scottish gardener, John Fyfiana, in the nineteenth century. This Gloxinia cultivars are available in a variety of flower colors and styles. hybrid was the basis for most modern gloxinia cultivars. groups; standard types may grow procedure with the exception of 20 to 24 inches in diameter with crop timing and pot size. Scope of Production 50 to 100 flower buds per plant and are grown in 6- to 7-inch Propagation Most growers produce glox- pots, compact types may grow 12 inias on a small scale. Producers Many growers today purchase to 18 inches in diameter with 50 usually obtain established seed- established seedlings of high qual- to 75 flower buds per plant and lings from specialized propagators ity cultivars from specialized prop- are grown in 5- to 6-inch pots, for either year-round production agators. However, excellent culti- and miniature types (minis) may or, more often, to meet holiday de- vars are available for the grower to grow 6 to 10 inches in diameter mands. The primary holidays are produce from seed. Gloxinia seed with 50 to 75 flower buds per Mother’s Day and Valentine’s Day. are very small (800,000 seed per plant and are grown in 4- to 4½- ounce). Therefore, seed should be inch pots. Mini types come in Cultivars sown in open flats (often wooden two flower types, tubular-shaped flats that are steam sterilized be- Gloxinia flowers mayARCHIVE be flowers, which sell the best, and tween use) using a fine-screened, single or double and come in a slipper-shaped flowers. Mini sterile, peat-lite medium that is 1½ variety of colors from pure white types generally have fewer pro- to 2 inches deep. A layer of coarse to pink, lavender, red, or dark duction problems and ship better vermiculite is added on top of the purple. Bicolors and those with than the other two sizes. They germinating media to hold mois- petals edged in white are very have more flexible foliage and ture. Gloxinia seed may be mixed popular. However, the velvet can be sleeved, which is difficult with sand and shaken thinly onto reds and purples outsell all oth- with the other two sizes. All size the vermiculite surface. Do not ers. Hybridization and selection types of gloxinia seedlings re- cover the seed. Germinate the seed has resulted in three cultivar size quire basically the same cultural

www.aces.edu using frequent light watering (no as needed. Allow the plants to pots loosely with potting medium mist) and with a 70- to 75-degree F acclimate for a day or two. It is and form a hole in the center soil temperature. Germination oc- not necessary to transplant the so the seedlings can be inserted curs in 10 to 15 days with a 65- to seedlings upon arrival, but they deep enough that only ¼ to ½ 70-degree F night temperature and a should be transplanted by no inches of the crown and two pairs 75- to 80-degree F daytime tempera- longer than 5 days. Seedlings left of leaves are above the soil line. ture. The light intensity during ger- in small containers too long can To do this, it may be necessary to mination should be no more than become stunted and will prema- bury the lower set of small leaves. 2,000 footcandles. Begin fertilizing turely set flower buds resulting in Do not intentionally break or re- seed flats a week after germination poor quality plants. move the lower leaves because at a rate of 150 to 200 parts per mil- Gloxinia seedlings are avail- this encourages disease problems. lion nitrogen applied 1 out of every able in 50-, 72-, or 105-celled flats Tall seedlings that may have 3 irrigations. Use a low- or no-am- for the standard and compact stretched during shipping will fin- monium fertilizer, such as 17-5-17. types, and the mini type seed- ish fine when planted this way. A one-time application of 20-10-20 ling also come in 200-celled flats. However, if they are not potted may be used to green the seedlings Which size a grower chooses to deep enough, they will be weak up if needed. Rinse the foliage with purchase depends on the cost and floppy when mature. Do not clear water after fertilizing. per seedling verses the amount pack the soil because poor media Once seedlings are large of time the grower has to finish aeration results in poor root de- enough to handle in germina- the crop. Small seedlings cost less velopment and stunted foliage. tion flats (30 to 45 days after and require more crop time while The newly potted plants can sowing), transplant them to 50 larger seedlings costs more and be held pot-to-pot for the first to 200 celled flats. Seedlings require less crop time. 4 weeks, then placed at a final flats are often picked out several spacing when leaves of adjacent times to select seedlings of uni- Potting Media plants begin to touch. It is critical form size for transplanting into In general, gloxinias require a to space plants on time. If leaves cell flats. Drench the cell flats light, well-drained potting media on adjacent plants begin to push with Banrot, Subdue, or Truban high in organic matter. To mix each other upward, crop quality to prevent diseases. B-Nine can your own, start with 50 to 60 may be reduced. Space the mini be applied as needed at 700 to percent peat and add perlite, ver- types in 4- or 4½-inch pots 9 to 900 parts per million to keep miculite, coarse sand, aged bark, 10 inches on center, plants in 5- the seedlings compact. Avid and or calcine clay for good drainage. inch pots 10 to 12 inches on cen- Sanmite can be used on seeding The media should be amended ter, and plants in 6-inch pots 12 to to control thrips that may damage with dolomitic limestone to a pH 14 inches on center. the young foliage and growing of 6.0 to 6.5. Superphosphate and point. Marathon can be used to micronutrients may also be incor- Disease Prevention control white flies and Nemasys porated at about half the recom- Always apply a fungicide can be used to control fungus mended rate. Many commercially drench after potting to guard gnats. Seedlings are transplanted available peat-lite mixes have also against diseases. Use Cleary’s into the final containers when been used successfully. 3336 plus Subdue Max, Cleary leaves begin to touch in the cell 3336 plus Truban, or Banrot. A flats, about 20 to 30 days in the second application of fungicide cell flats depending on the time Potting Gloxinias may be grown in 4-, may be applied 6 weeks after the of year. Gloxinias may also be first application for complete dis- propagated from tubers or leaf 4½-, 5-, 6-, or 7-inch pots depend- ing on the cultivar size group and ease control that will last the en- cuttings, but these methods are tire production period. A light fo- rarely used commercially. the size finished plant desired. Within a size group, a larger pot liar rinse with clear water should ARCHIVEbe applied after the fungicide will produce a larger plant and Handling Purchased drench to eliminate possible inju- Seedlings a smaller pot will produce a smaller plant. Before removing ry to foliage and unsightly residue. Unpack the seedlings and ex- the seedlings from the cell flat, amine them closely for potential hold the flat at each end and flex Watering problems such as insects, diseases, the center of the flat upward to Gloxinias thrive best when or shipping damage. Contact the loosen the soil balls from the cell the soil is maintained uniformly propagator promptly if problems interiors. This helps prevent dam- moist. However, they should not are found. Place the seedlings aging the seedlings when they are remain wet for long periods in in a greenhouse and water them removed from the flats. Fill the 2 Alabama Cooperative Extension System winter. Plants in small pots should symptoms of excess fertiliza- foliage appears yellow or mottled, never dry out to the wilting point. tion or high ammonium nitrogen. growth is hard, or small gray- If they do, flower buds may set These symptoms can occur in the brown spots appear on the leaves, prematurely and the plants will winter when plants require water add more shade. flower before reaching the desired less frequently and less leaching size. Gloxinias can be watered takes place. The recommended Supplemental Light overhead with a hose and water electrical conductivity standards Dark, overcast weather in the breaker, especially in the early for gloxinias are 0.76 to 2.0 winter can delay gloxinia growth. stages, as long as the water is tem- mmhos/cm using the saturated Supplemental light from high pered and the greenhouse is not media extract method, 0.7 to 1.0 intensity discharge lamps (metal too hot and bright. In all seasons, mmhos/cm using the 2:1 method, halide or high-pressure sodium) it is a good practice to water early and 1.0 to 2.6 mmhos/cm using can be used to supplement ambi- in the morning so the foliage drys the pour-through method. ent sunlight and speed progress quickly. It is important that the of the crop by several weeks in water temperature be close to the Boron Deficiency the winter. The lamps should air temperature when overhead Watch for boron deficiency supply about 200 footcandles at irrigating. If the water is too cold during periods of high light in bench level and be turned on for (below 50 degrees F), bleached the summer. This problem usu- 14 to 16 hours per day (6:00 a.m. rings may appear on the leaves ally appears before the plants get to 10:00 p.m.). Supplemental light called ring spot and roots may be large and may be confused with is more economical if applied to damaged. Many growers temper chewing insect damage. Crown cell flats or during the 4 weeks their water with large water heat- leaves will be deformed and ap- plants spend pot-to-pot because ers or heat exchangers associated pear eaten around the edges. If fewer lamps will be required to with the boiler heating system. At the leaves have holes or slits, the light the crop compared to after the final spacing, many growers problem is not boron deficiency they are spaced out. Young plants use microtubes, capillary mats, or but more likely insects, such as also respond more to supple- ebb-and-flow watering systems to thrips. Boron deficiency usually mental light than older plants. avoid water contacting the foliage occurs in soilless media with little Supplemental light is useful for and flowers and to provide greater or no micronutrients The problem standard and compact gloxinias, watering uniformity. is easily solved using a spray of especially in northern climates. Borax at ½ ounce per 1,000 gal- Fertilization lons, or 1 gram per 75 gallons. Temperature Begin fertilizing seedlings For best growth, the night transplanted to the final contain- Light temperature should be 65 to 68 ers about 10 to 14 days after Light intensity for seedling degrees F and 70 to 75 degrees potting. Alternate 17-5-17 and 20- flats and cell flats should be kept F during the day in the winter. 10-20 during the warmer months low, about 2,000 footcandles Progress of the crops can be and use 17-5-17 alone in the measured at noon on a clear day. speeded up or slowed down by cooler months at a rate of 200-250 Removable shade cloth can be increasing or decreasing the night parts per million nitrogen. Apply used on the greenhouse for this temperature. Do not exceed 90 fertilizer 1 out of every 3 irriga- stage. Finish plants should re- degrees F during the day in the tions. Use the lower rate in the ceive 2,000 to 3,000 footcandles summer, and do not reduce the winter and the higher rate in the depending on the time of year. night temperature below 62 de- summer. Plants on subirrigation During the winter season, higher grees F in the winter. Greenhouse systems can be fertilized at a rate light intensities can be used when temperatures of 45 degrees F or of 125 parts per million nitrogen. temperatures are more control- lower will cause plant damage. Slow-release fertilizers, such as lable and the number of hours Low day or night temperatures Osmocote 14-14-14, can be used ARCHIVEof natural light are short. In the in the winter can delay gloxinia at one-fourth the recommended summer, lower light intensities growth. Careful attention should rate. However, avoid a 20-20-20 are best to help control heat. A be paid to proper ventilation and fertilizer or any fertilizer with 60 percent shade cloth is often reducing relative humidity during more than 40 percent of the total used. Many growers in northern the winter to reduce condensation nitrogen in the ammonium form parts of the United States can and prevent diseases. Conversely, because these have resulted in get by with full sun in the winter high relative humidity is impor- foliar disorders. Twisted, cupped, months. If plants start to stretch tant during the hot, dry weather or curled leaves with a general and have low flower bud counts, deep blue-green color are often remove some of the shade. If the 3 in the summer. At this time, paths, depending on the time of the year should be above 45 to 50 degrees empty bench tops, and green- and geographic location. Starting F, or plant injury will occur. house side walls can be wet from seed, large-growing types re- down to raise the humidity. quire 20 to 27 weeks. Seed can be Gloxinia Cost of Production sown in August for Valentine’s Day The following budgets typify Growth Regulator sales and in November for Mother’s the cost of producing and market- B-Nine can be applied as a Day sales. The compact types gen- ing about 500 gloxinias in differ- spray at a rate of 1,250 parts per erally require 4 to 8 weeks less ent container sizes. million, 10 to 14 days after pot- time than the standard gloxinias. ting or when the first set of leaves For growers who order seed- Cultural Problems reaches the pot edge to prevent lings from propagators, time to fin- ish is about 10 to 14 weeks for the • Premature flower buds may main stem and petioles from be caused by leaving plants in cell stretching. A second application large growing types, 6 to 10 weeks for the compact types, and 7 to 10 flats too long, excess heat or light, can be applied 7 to 10 days later, lack of nitrogen, or allowing very if needed, to the standard types weeks for the mini gloxinias (Table 1). The variation in time to finish in small plants to dry out too much under low light conditions. Under before potting. proper cultural conditions, i.e. different seasons reflects changes in light levels and watering practices, light levels and temperatures. • Twisted, curled, or cupped a second application is often leaves are caused by some type unnecessary. One application Disbudding of fertilizer toxicity, such as high ammonium in winter, or by cold or no growth retardant may be Growers often remove the first drafts. needed for the compact types. Do pair of dominant flower stalks that not apply B-Nine to mini types. arise from the canopy before they • Deep blue-green foliage that All B-Nine applications should be show color. A few of the upper- may appear stunted is caused by completed in the first 3 weeks most leaves may also be removed excess fertilizer or excess B-Nine. after potting. If plants need if the center is congested to ex- • Flowers hidden under the fo- additional height control toward pose the remaining flower buds to liage or plants remaining in a veg- the end of production, Bonzi at a light. This results in a flush of 6 to etative state without flowers are rate of 15 parts per million gives 8 flowers opening at one time–-a usually caused by excess fertilizer, good height control without showy gloxinia product. high ammonium, or too low day delaying flowering. night temperature. Postharvest • Yellowing of leaves with Scheduling lighter yellow areas between the If plants are sleeved and veins is caused by excessive sun- The schedule shown in Figure placed in a box, flower buds light, high ammonium fertilizers, a 1 is a generalization and individual showing color will open during combination of high light and too stages may require a week less shipment. Shipping temperatures than indicated or a week more little nitrogen, or root loss due to high soluble salts or overwatering.

Table 1. Production Time for Standard Gloxinias in 6-inch Pots

Weeks to finish from: Winter Spring Summer Fall

2¼-inch liner 13 - 14 12 10 11-12

1½-inch liner 13.5-14.5 12.5 10.5 11.5-12.5

Production Time for Compact Gloxinias in 4½-inch Pots Weeks to finish from: ARCHIVEWinter Spring Summer Fall 2¼-inch liner 9-10 8 6-7 7-8

1½-inch liner 9.5-10.5 8.5 6.5-7.5 7.5-8.5

Production Time for Mini Gloxinias in 4-inch Pots

Weeks to finish from: Winter Spring Summer Fall

200 plug 9-10 8-9 7-8 8-9

Greenhouse Production of Gloxinia 4 General Production Schedule, Standard Gloxinia Naturalis to plants without flowers. Conserve and Mesurol can be used if populations are high. Thrips 2-3 wks 4-5 wks 4-5 wks 4 wks 6-10 wks feeding on flowers is a difficult GerminationCell flat Final space problem because the delicate open Sow Transplant Finish blooms of gloxinias are subject to seed to final damage by many insecticides. Avid container and Sanmite can be applied to Figure 1. For growers who order seedlings from propagators, time to finish is about flowers open. 10 to 14 weeks for the large-growing types, 6 to 10 weeks for the compact types, and 7 to 10 weeks for the mini gloxinias (Table 1). The variation in time to finish in Disease Problems different seasons reflects changes in light levels and temperatures. Botrytis blight, Myrothecium, Insect Problems on leaf tips and margins. Spots Phytophthora, Pythium, and viruses can infect gloxinias. Caterpillars, cyclamen mites, become dry and dull black. Greenhouse sanitation procedures foliar nematodes, spider mites, Destroy infected plants. Water can go a long way toward pre- and thrips can be problems on plants in a manner that keeps leaf venting these problems. gloxinias. However, thrips are the surfaces dry and does not splash most difficult. water from plant to plant. • Botrytis Blight causes small water-soaked lesions that form on • Caterpillars chew the leaves • Broad mites and 2-spot- infected petioles and spread to of gloxinias and are most likely to ted spider mites occur mostly leaf blades. Infected flowers fade be a problem in summer or fall. on the underside of leaves and prematurely. Space plants and Apply Dipel, Conserve, or any of their feeding causes a mottled provide ventilation to avoid high the pyrethroid insecticides labeled or speckled appearance on the humidity. Remove fading flow- for caterpillars. upper leaf surface. Spider mites can develop quickly under warm, ers and yellowing leaves. Apply • Cyclamen mites are too dry conditions. Apply Talstar. Decree or Compass. Do not use small to be seen without a mag- Chipco 26019 or Cleary because nifier, but may be detected by • Thrips can attack the grow- ing tips of small plants and cause they leave an unsightly residue stiffening and discolored reddish on the foliage. brown young leaves. Use Talstar the leaves to grow out deformed • Myrothecium causes peti- for light infestations and Pylon for with cuts, holes, or ragged edges. oles of lower leaves to develop heavy infestations. Develop a spray rotation of several different insecticides with different darkened spots. The spots enlarge • Foliar nematodes cause modes of action. Good success has down the stems and stems are small tan, sunken areas to form been achieved with BotaniGard or easily broken. Plant in clean

Table 2. Estimated Variable Costs of Producing Gloxinias in the Southeastern U.S. Salable crop = 500 in 6-inch pots. Crop timing is 50 plug = 12 weeks, 72 plug = 13 weeks of production. Materials Description Unit Quantity $/Unit $/Crop $/Unit $/Crop

Plugs 50 plug each 500 $0.55 $275.00

Plugs 72 plug each 500 $0.51 $255.00

Shipping Average for S.E. states each 500 $0.05 $25.00 $0.05 $25.00 6-inch press fill pots Pots case 1 $0.06 $30.00 $0.06 $30.00 (500 per case delivered) 3 cubic foot bags Media ARCHIVEbag 11 $0.20 $99.00 $0.20 $99.00 ($9.00/ bag delivered) ID Tags 300/bundle (color printed) each 500 $0.02 $10.00 $0.02 $10.00

Fertilizer Peters 15-16-17 bag 1 $0.05 $20.50 $0.05 $20.50

Pesticide Banrot bag 1 $0.15 $57.00 $0.15 $57.00

Total $1.08 $516.50 $1.04 $496.50

5 Alabama Cooperative Extension System Table 3. Estimated Variable Costs of Producing Gloxinias in the Southeastern U.S. Salable crop = 500 in 4-inch pots. 50 plug = 9 weeks, 72 plug = 10 weeks, 200 plug = 11 weeks of production. Materials Description Unit Quantity $/Unit $/Crop $/Unit $/Crop $/Unit $/Crop

Plugs 50 plug each 500 $0.55 $275.00

Plugs 72 plug each 500 $0.51 $255.00

Plugs 200 plug each 500 $0.25 $125.00 Average for S.E. Shipping each 500 $0.05 $25.00 $0.05 $25.00 $0.05 $25.00 states 4-inch press fill pots Pots (500 per case deliv- case 1 $0.04 $20.00 $0.04 $20.00 $0.04 $20.00 ered) 3 cubic foot bags Media ($9.00/bag deliv- bag 4 $0.07 $36.00 $0.07 $36.00 $0.07 $36.00 ered) 300/bundle (color ID Tags each 500 $0.02 $10.00 $0.02 $10.00 $0.02 $10.00 printed) Fertilizer Peters 15-16-17 bag 1 $0.04 $20.50 $0.04 $20.50 $0.04 $20.50

Pesticide Banrot bag 1 $0.12 $57.00 $0.12 $57.00 $0.12 $57.00

Total $0.89 $443.50 $0.85 $423.50 $0.59 $293.50 media and do not reuse contain- • Pythium root rot causes necrotic spot virus, tobacco mosa- ers. Apply Chipco 26019 to leaves dark brown roots. Plants wilt, yel- ic, tomato spotted wilt, or tomato and stems. Maintain moderate low, and die. Pot in clean media ring spot virus can be problems temperatures and low humidity. and destroy infected plants as on gloxinias. Impatiens necrotic • Phytophthora crown rot soon as they show symptoms. spot is probably the most serious causes roots to have a dark, Apply Banol, Banrot, Subdue 2E, and widespread. Maintain good water-soaked appearance. This Terrazole, or Truban to protect thrips control including screening spreads to petioles and leaf healthy plants. them out with fine-mesh screen. blades. Young plants are often • Virus infection symptoms Destroy infected plants. Eliminate quickly killed. Pot in clean media vary. Leaves may have dark weeds within the production area and destroy infected plants as brown to black dead areas in line and within 30 feet outside the soon as they show symptoms. patterns. Flower petals may be greenhouse. Do not use tobacco Apply Banol, Banrot, Subdue spotted. Leaves may be down- products when handling plants. 2E, Subdue MAXX, Terrazole, or wardly cupped, mottled, or nar- Keep gloxinias away from other Truban to protect healthy plants. rowly shaped. Leaves may have crops known to be susceptible to line or ring spot patterns. Shoots impatiens necrotic spot virus. may be elongated. Impatiens

ARCHIVEJ. Raymond Kessler Jr., Extension Horticulturist, Professor, Horticulture, Auburn University For more information, call your county Extension office. Look in your telephone directory under your county’s name to find the number. View more information on specific chemicals (product labels, MSDSs) at http://www. cdms.net. Issued in furtherance of Cooperative Extension work in agriculture and home economics, Acts of May 8 and June 30, 1914, and other related acts, in cooperation with the U.S. Department of Agriculture. The Alabama Cooperative Extension System (Alabama A&M University and Auburn University) offers educational programs, materials, and equal opportunity employment to all people without regard to race, color, national origin, religion, sex, age, veteran status, or disability. 2.1M, New Sept 2004, ANR-1258

ANR-1258 2004 by the Alabama Cooperative Extension System. All rights reserved.