Gerbera - Decorative Daisies

Gerbera hybrida, the Florist Gerbera, is probably the world’s most decorative daisy. Amongst the most popular, widely purchased of all Florist flowers sold today. Gerberas rank as the number one Florist Daisy sold commercially around the world.

And always within the top 10 most favourite Florist flowers ranking along with the Rose, Carnation, Chrysanthemum, Tulip and Lily, and ahead of Freesia, Cymbidium Orchid, Alstroemeria and Gypsophila. They come in a staggering array of shapes, colours and sizes on lovely, long stems.

New hybrid strains have been introduced from Australia, England, Holland, Japan, New Zealand as well as their native South African homeland.  Almost all of these thousands of hybrids originated from a cluster of small wildflowers of the Transvaal, G. jamesoni, the Barberton Daisy.

Barberton Daisy is rather humble and sparse plant somewhat reminiscent of a Dandelion in habit of growth, with similar leaves and slightly larger, orange, red or yellow ray-petaled flowers. This pretty wildflower has been repeatedly cross-bred with itself and the other 40 species from South Africa, and a few species from Asia and the Indian Ocean.

All this cross-breeding has created today’s splendid array of remarkable hybrids. Today the hybrid Florist Gerbera or Gerber Daisy hardly bears much resemblance to its humble origins.

Gerberas are stemless perennial herbs with rhizomous roots and crowns. Each crown forms a basal rosette of erect, somewhat hairy, long and often deeply toothed leaves creating large clumps of foliage around a central internal centre. The flower buds arise from the crown centres on long, stout stems.

Each tall, sturdy stem usually carries one large, elegant, ray-petaled daisy.  There are many hybrid cultivars of various sizes. A few very hardy garden varieties still closely resemble the Barberton Daisy. They have fairly short thinner stems 12-18in/30-45cm sometimes taller producing multiple flower stems that nearly reflect the wild species often in the same orange, red and yellow tones.

The modern hybrids come in a wide variety of dwarf forms quite suitable for containers and even growing indoors. These are usually 12-18in/30-45cm in a full range of double, semi-double and single flower forms produced on somewhat thicker stems. Petals are generally broader and of a more substantial texture as produced in the large Florist Gerbera hybrids.

The modern Florist Hybrid Gerberas come in an almost complete rainbow of colourful shades and an endless variety of forms. These are often much bigger plants producing robust leafy growth often 60cm-1m/24in-3ft across with dramatically tall flower stems in some hybrids reaching 2-4ft/60-120cm. These are often grown in special glasshouses for the Florist Trade and are often a bit difficult to grow successfully outdoors in most average climates due to adverse weather extremes and fluctuations.

Most Gerberas, especially the dwarf and hardy hybrids will grow very well outdoors. They do best in moderate climates, in sheltered sunny, warm spots experiencing little if any frost. In such locations they will flower outdoors all Winter and Spring. And where Summers are benevolently cool to moderate Gerberas can flower right into Autumn. They are such a versatile flower that with a little coaxing, most all species and especially the Florist hybrids can be had in flower almost all year in the glasshouse.

Blooms are usually cut just as their buds first open. When cutting, one must be cautious as buds and stems can be brittle if the weather is cool and buds and stems are filled with water. Because of this, stems can snap, often where the bud joins to the stem. Consequently Florist Gerberas are often shipped with a clear plastic collar protective sheath wrapped around each flower. This also helps protect the petals from bruising in transit.

Because stems are hollow they can also bend or partially break or ‘crease’. Florists often extend a thin wire up through the stem and into the centre of the flower to avoid this possibility. And another Florist secret to preserve their flowering life or to revive a wilted stem is to recut the stem at its base and plunge just a few centimetres into very hot (but not boiling) water for a minute or so. This seals the stems from ‘bleeding’ and pushes extra sap up into the upper stem and flower to keep it erect and sturdy.

Gerbera foliage is frost tender but the rootstock can withstand light freezing under dry conditions. Foliage will withstand a couple degrees of frost without much damage but will often ‘bronze’ in the cold. But any significant freezing will certainly result in burnt leaves. It is best to leave them attached as a protectant against further freezing deeper into the sensitive crown. If that freezes the Gerbera often dies but occasionally will spring back from its rootstock.

Some people in borderline frost areas will partially cover around the plants with light fluffy mulch like dry leaves or straw or cover over them with protective frost cloth. Whatever is used must remain light and airy. For if any protective mulch or covering becomes packed, sodden and wet, or deeply shades out the sunlight, this can rot out the crown.

Gerberas celebrate their South Africa heritage with a strong love of bright to full sun positions with excellent air flow but sheltered from winds. They prefer relatively moderate to low humidity and constant warm temperatures.  Perfect drainage is essential.

Gerberas love sand, sandy soils and other freely draining open soils which allow their roots to deeply penetrate. They thrive in a variety of light soils if deeply enriched with aged manure, blood and bone and generous Lime. Being natives of arid and drier climates, their fleshy roots have learned to naturally adapt to potentially dry conditions by penetrating and spreading deeply where subsoil moisture is more likely available during times of drought.

It is possible to grow Gerbera in heavier and even wet soils. Lighten heavy soils with at least a generous shovel of sand or round river gravel per plant. Make sure a good deal of this sand is placed in a pocket right around the plant and that the site is sloping or elevated.  Alternatively grow the Gerberas on mounds or in raised beds above the wet land. This will provide the perfect drainage they will need.

Gerberas thrive in larger rather deep containers or glasshouse beds. Many of the specially designed dwarf hybrids are excellent for smaller pots on sunny windowsills, window boxes or under agricultural ‘Gro’ lights indoors.

Gerberas are gross and heavy feeders. They have a particular fondness for Potassium (Potash). Usually best results occur when the plants are bedded in a deeply dug soil well enriched with aged manure and/or mature compost. Dust over the ground with a good well-balanced General Garden Fertilizer and another dusting of Sulphate of Potash or untreated wood ashes.

Gerberas also respond very well to regularly light side dressings with Rose Fertiliser. Gerberas have almost identical mineral requirements to Roses so can be fed and sprayed with the same formulas and preparations. For this reason, Gerberas and Roses are often grown in the same bed. The Roses shelter the Gerberas from excessive burning sunshine on their flower petals as well as providing some protection from strong winds.

The Gerberas broad and leafy foliage spreads over the ground between the Roses which provides some cooling shade and moisture retention for the Roses. Thus Gerberas and Roses make excellent companion plants! And for that extra boost near flowering time, foliar feed both with a balanced buy higher Phosphorous and Potash foliar fertiliser  (10-20-30; 5-15-45), etc. with extra trace elements added as buds appear.

Gerberas do like their water. Even though they come from arid regions and demand perfect drainage, regular watering is equally important as regular feeding. Water deeply during dry periods but let the plants dry out before watering again. They respond well to light mulching with granulated bark, dry compost, aged manure, pea straw, etc. which helps maintain an even supply of moisture for their roots.

Gerberas are easily raised from seed. This can be gathered from mature seed heads during Spring and Early Summer or purchased commercially. Seed is best planted immediately as it does not keep for very long. Seed is genetically quite variable so what is collected from any particular flower will produce a variety of offspring. Even when seed is collected from a strong cultivar, that seed will often produce very different offspring from the parent creating exciting new hybrids!

Seed is best sown from Spring through Summer so that plants will be mature enough to transplant into their permanent beds or containers by Late Summer or Autumn. Depending on climate and growing environment, they will begin flowering during Late Winter or in the Spring.

Seed will grow well in a mix of ½ peat and ½ perlite or a mix of 1/3 sand, 1/3 loam, 1/3 peat and sterilise this by baking at 400F/204C for one hour. Sow seed thinly into flats, punnets or individual pots of this pre-moistened seed raising mix. The pointed end of each seed should face down into the mix with the fluffy end upward. Barely cover the seed with more mix and mist over this to moisten it.

Place the seed containers in a very airy, bright, humid and warm environment. This could be under glass or even a sheet of newspaper; in a propagation box; placed inside a plastic bag drawn up loosely around the containers to create a terrarium; or outdoors if environmental conditions are suitable.

Gerbera seed needs light to germinate as well as adequate moisture and constant warmth. Germination usually occurs with 10-14 days but can take longer under less than ideal conditions and can sometimes be a bit erratic. Should temperatures drop during the germination period insure that the seeds are never over-watered or they are prone to rotting. Proper air circulation is also essential especially as young seedlings emerge or the young seedlings may fall victim to damp-off fungus and collapse at an early age.

Liquid feed young seedlings regularly and maintain adequate air, light, warmth and water. Once the young seedlings have established two or more pairs of mature leaves they are transplantable and can be pricked out into individual pots for growing-on. Always transplant the seedlings just a bit high in the soil or onto small mounds of earth and firm them into position. This is important so that excess water always drains away from the seedling crown and never collects in a basin around the seedling which would result in crown rot.

Usually the young seedlings are either grown on in a glasshouse bed or nursery in small containers until they are strong enough to be planted into their permanent position outdoors in Late Summer through Early Winter. Once they are planted out, provide a generous 60cm/24in/2ft between plants. Crowding plants often leads to inferior flowering, poor plant health and often the least hardy will ultimately die out.

Make sure that their permanent planting bed is in full sunshine with good air circulation, but protected from strong winds and hard frosts. Soil must be enriched, freely draining and well-worked as mentioned earlier. Gerberas make excellent plantings for a glasshouse crop, especially because external environmental conditions like excess rainfall and inconsistent temperatures can be controlled. Most problems experienced growing Gerberas both indoors and outside are exactly the same as for Roses. Probably more spraying will be necessary to control botrytis and mildew when grown in the glasshouse or indoors than when grown outdoors.

Once established, the plants can be left to grow and multiply for 2-3 years before they will need to be divided. If grown in containers, they are usually potted on annually directly after flowering finishes or in the Autumn.

Once plants become established, cut off dead and yellowing foliage and remove spent blooms and stems as they finish unless they are meant for seed. After flowering finishes, leaves are often cut back in Late Summer or Autumn to encourage new crowns and healthy, strong new foliage that will support the next flush of flowers.

Because Gerberas are so genetically variable, it is possible to develop very attractive and unusually hybrid cultivars. Many of these will be worthy of keeping. Each plant will mature and continue to multiply for several years up to nearly a decade before it will be spent. During that time the only way to do increase the numbers of valuable cultivars is through plant cloning or division. Division is the only way the home Gardener can maintain special colours and named varieties.

Established plants with 6 crowns or more can be divided in Autumn through Early Winter or later in Mid/Late Spring immediately after flowering has finished. Dig the clumps from well away from the central crown and lift to bring up the entire root mass. Shake off all excess soil. Work the crowns with roots attached back and forth and they will often separate naturally into separate pieces. Each crown must have at least a few roots attached in order to produce a new plant.

Leaves and roots are cut back and shortened to 10 cm/4in. and immediately replanted into a well-enriched light soil. Make a generous hole and fill into the centre with a cone of soil creating a small mound. Rest the crown upon the top of this mound with roots dangling down and spreading outward in all directions. Be sure that the crown rests above the surrounding soil line so as to avoid later rot.

Then back fill dirt up around the roots and firm into position. If the crown drops below soil level, grasp it firmly and very gently pull it upwards and add more soil underneath until it rests well above the surrounding soil. Then water it in immediately and make certain that when the water further settles the soil that the crown remains high above the surrounding soil in the bed to insure perfect drainage.

In the Language of Flowers, the Gerbera is the symbol of ‘Innocence and Purity’. Certainly these decorative daisies live up to that reputation. And like the other members of the Daisy Family, they also represent ‘Beauty, Cheer, Loyal Love, and Simplicity’ and are sometimes used as a symbol of ‘Sincerity’.

Any Garden Lover willing to spend the time growing these fabulous flowers will soon understand why the decorative Gerbera has earned this wonderful reputation!

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