Greenhouse Production of Gloxinias
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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.