Publication #CIR527
Gerberas for Florida1
Description
Gerbera or Transvaal daisy (Gerbera jamesonii Bolus ex. Hook f.) is a flowering perennial that belongs to the Compositae family. Recent introductions of new hybrids have resulted in a resurge in their popularity. Gerberas can be used in landscapes as bedding plants for borders and flower beds or as cut flowers for table arrangements.Gerberas are native to Transvaal, South Africa, where they grow in full sun. They will tolerate 30°F (-1°C) without adverse effect if protected from frost. Plants will overwinter in central and north Florida in areas where prolonged hard freezes are not experienced.Gerberas usually begin blooming when plants are 12 inches (30.5 cm) tall or taller. Leaves are long, slender, pubescent on the under surface and pinnately lobed or parted with leaf blades 5 to 10 inches (12.7 to 25.4 cm) long and 2 to 4 inches (5.1 to 10.2 cm) wide. Each crown possesses numerous leaves and flower stalks with plants eventually forming a dense clump.Hybrid gerbera varieties cloned through tissue culture are uniform, and have long-lasting flowers with thick peduncles that are not light sensitive; hence, flowers remain open in the dark, lending themselves to indoor use in flower arrangements. Flower Colors and Forms
Gerbera flowers often measure 7 inches (17.8 cm) across and can be colored light to dark yellow, orange, pink, brilliant scarlet and deep red. Some clones have flowers with brown or dark centers (eyes). Flower forms can be divided into five distinct groups. Single. Singles have a row of nonoverlapping petals (ray florets) with a green center (disc florets). These are the most common gerberas on the market. Double or duplex. These have a double row of overlapping petals with a green, black, or dark red eye. Crested doubles. These doubles contain two rows of overlapping petals with one or more inner rows of shorter petals with a green, black, or dark red eye. Full crested doubles. These have solid overlapping rows of petals with an inner row diminishing in size, covering the eye entirely. Quilled full crested doubles. This type possesses solid overlapping rows of split petals with a fine textured appearance. Planting and Care
Gerberas grow best in well-drained, sandy soils amended with organic matter for nutrient and water retention. One to two inches (2.5 to 5.1 cm) of peat or other organic material can be incorporated into the soil before planting. Dolomitic limestone at a rate of 3 pounds per 100 square feet (1.5 kg/10 m2) also should be incorporated before planting.Small plants (seedlings) can be purchased in small compartmentalized trays in early spring from garden supply stores, chain stores and local nurseries in north Florida and in early fall in central and south Florida. These small plants can be transplanted directly into the landscape using a spacing of 12 to 18 inches (30.5 to 45.7 cm). Plant to a depth where plant crowns are visible after watering. They require about 7 to 10 weeks of growing time before they bloom.Plants purchased in compartmentalized containers should be transplanted as soon as possible, preferably the same day of purchase. Flower beds should be prepared before plants are purchased. Plants grown in small compartmentalized trays usually have pot-bound root systems. If these are planted without disturbing, the root system will be slow to establish with the surrounding soil, and the plants will suffer from lack of moisture if not watered daily. A preferred method is to loosen and untangle the root system without breaking the soil ball. Plants will usually recover rapidly and become established quickly.Excessive moisture during the rainy season may increase the incidence of root disease. Growing gerberas in raised beds or mounds allows excess moisture to drain rapidly to alleviate or reduce this problem.Mulching with organic material to conserve some moisture and reduce solar heating of soil is beneficial. Black plastic mulches should never be used, except when a layer of organic mulch is added on top of the black plastic.Gerbera crowns gradually sink into the soil after a period of growth. The crown becomes entirely submerged after a year or two, and excess moisture at this time tends to induce crown rot organism infestation, causing crowns to gradually weaken and die. Plants should be dug after two years and replanted to keep crown rot under control.Gerberas respond to high fertility levels and should be fertilized on a regular basis. A complete fertilizer (12-4-8, 15-5-15, etc.) should be applied at a rate of 1-1/2 pounds per 100 square feet of bed area every month during the growing season (March-October for north Florida and February-November for central and south Florida). Gerberas respond best to controlled release or organic fertilizers which slowly release nitrogen over a long period of time.Gerberas grown in Florida's sandy soils often express deficiency symptoms for the microelements iron and manganese. A microelement fertilizer should be incorporated into the soil before planting. If deficiency symptoms appear after plants have been grown for a period of time, spray with a liquid microelement formulation to correct the problem.Gerberas are full sun plants, but they will also thrive under 30-50% shade. Spent blooms and old leaves should be removed promptly to avoid possibilities of disease infestations. Dead tissue usually serves as an entry point for disease.Large specimen plants are available at some garden supply stores and nurseries. They are more expensive plants that have usually been propagated vegetatively by tissue culture and grown to maturity. Most are sold in 5 1/2- to 6-inch plastic pots and are in bloom when purchased, making color and flower type selections easy. Rather than waiting for smaller seedlings to produce flowers of unknown color and form, these plants provide instant color in flower beds. Specimen plants do not have to be transplanted right away and can be grown in pots, placed under partial shade and watered when needed. Plants left in pots should be fertilized weekly with a water soluble fertilizer such as 20-20-20 at a rate of 1 tablespoon per 2 gallons (15 ml/L) of water until they are ready to transplant into beds. These plants can also be transplanted into 3-gallon pots and placed on patios, decks, around swimming pools, or along driveways. Seeds
The most inexpensive way to produce gerberas is from seed obtained from reputable seed companies throughout the United States. However, plants propagated from seed are usually not true to type and may vary greatly in flower color.Seed should be germinated in an artificial growing medium. Germinating seed in field sand or field sand mixed with materials such as perlite and/or peat moss is not recommended because field sand is usually not sterile and may contain weed seed, nematodes, insects and fungi. Artificial growing media that are sterile, lightweight, and have good water retention capacity and drainage can be purchased in garden supply stores. These materials often have fertilizers incorporated.The medium can be placed in flats or pots that have drainage holes. Make shallow rows in the medium approximately twice the depth of the diameter of the seed, sow seeds in the rows, cover lightly with extra medium and water carefully.Artificial mixes containing peat moss are difficult to wet when dry; thus they should be watered thoroughly before planting seed. After seeds are planted and watered, cover the container with a sheet of glass or clear plastic and place the germination container approximately 18 inches (45.7 cm) below a fluorescent light. Check the medium daily for moisture and for signs of seed germination. The medium should never be allowed to dry, especially when seeds are starting to germinate. When watering is necessary, apply a sufficient amount to allow excess water to drain out of the container. Any water that collects in the saucer beneath the germination container should be discarded. Allowing germinating seeds to remain in excess water will damage the root system. Tall and spindly seedlings can be avoided by transplanting seedlings to small pots as soon as the first true leaves appear. Seedlings can be grown in small pots until they are large enough to transplant into flower beds. Division
Desired cultivars can be obtained by dividing parent plants. One-year-old plants consisting of multiple crowns can be dug and divided at any time of year in south Florida and during spring and summer in north Florida. Plants should be lifted and cleaned, and each crown separated with a clean sharp knife or pruning shears. Dead roots and old decaying leaves should be removed. Plants can be soaked in a solution of 1 part liquid bleach and 10 parts water for 10 minutes to avoid spreading diseases. Extending the soak time could damage or kill the plant. Remove one half of all mature leaves by cutting crosswise approximately halfway between the petiole and distal end of the leaf blade. Plants should be replanted immediately and kept moist to minimize wilting. Pests and Diseases
Gerberas have insect and disease problems, and to successfully grow specimen plants these problems must be recognized and control measures initiated.Insects that attack gerberas also are common to many other plants. The most destructive are leaf miners, which are tiny flies that deposit eggs on the leaves. Resulting larvae bore tunnels between epidermal layers of leaves. These tiny larvae feed as they bore tunnels and produce white streaks on leaves. Heavy leaf miner infestation can cause a collapse of cells and eventual death of parts of leaves, which gradually turn brown. These areas become an ideal place for secondary fungal organisms to become established. There is little that can be done when larvae are feeding, since they are protected from most insecticide spray by the leaf epidermal layer. Periodic pesticide application may minimize additional infestation.Caterpillars, leaf chewing worms, and cutworms can also be destructive. Plants attacked by caterpillars have ragged leaves that may suddenly wilt and turn brown when young leaf petioles are damaged.Thrips and red spiders can also be a problem. These are minute insects that rasp and suck juices from plant cells. They often go undetected because they usually feed on the undersides of leaves. Infestations are most severe when plants are subjected to prolonged water stress during hot dry weather.A number of fungal organisms affect gerberas. Some of the more important ones are gray mold and powdery mildew. Gray mold is caused by the fungus Botrytis cinerea, which attacks dead plant parts, and, when conditions are favorable, feeds on living leaf and flower tissue. Sources of infestation can be avoided by removing dead or spent flowers and dead or dying leaves promptly.Powdery mildew is a problem usually occurring when plants are subjected to prolonged wet, humid weather. Powdery mildew requires moisture before it can become established. If leaves remain dry and sufficient air movement is present, it will not become a problem. Specific insect and disease control recommendations can be obtained from your local county extension office. Footnotes
1. This document is Circular 527, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. First published: June 1990. Reviewed: February 1991. Reviewed and revised October 2003. Please visit the EDIS website at http://edis.ifas.ufl.edu
2. B. Tjia, former extension floriculture specialist; R.J. Black, professor emeritus, consumer horticultural specialist, Environmental Horticulture Department, Cooperative Extension Service, Insistute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611.The Institute of Food and Agricultural Sciences (IFAS) is an Equal
Opportunity Institution authorized to provide research, educational
information and other services only to individuals and institutions
that function with non-discrimination with respect to race, creed,
color, religion, age, disability, sex, sexual orientation, marital
status, national origin, political opinions or affiliations.
For more information on obtaining other extension publications,
contact your county Cooperative Extension service.
U.S. Department of Agriculture, Cooperative Extension Service,
University of Florida, IFAS, Florida A. & M. University Cooperative
Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.
