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Gerbera Cups - The packaging solution to protect the gerbera flower!
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Bonbini |
Charlene |
Cherany |
Cobra |

Although we trust that this cultivation guide will be of considerable help to the success of the crop, we cannot accept any liability for the results of your crop. All the information in this guide is without committing ourselves.
1. Introduction.
Gerbera is one of the most important cut-flowers, successfully grown under different conditions in several areas of the world and meeting the requirements of various markets. This success is primarily due to the wide range in colour and shape of the flower. The gerbera plant was first contributed by Robert Jameson in South Africa.
In the past, all Gerbera's where grown from seeds and cuttings. This changed in the seventies, when techniques for multiplication with in-vitro became available. These methods allowed a different approach in breeding and selection of Gerbera. Founded in those days, Preesman B.V. is one of the companies with a selection programme based on scientific methods. These selections were very successful; several varieties from those days are still on the market (e.g. ‘Delphi’). Presently, Gerbera is a plant which is multiplied 100% in-vitro, the most modern way of propagation in horticulture. Using this technique, it is possible to produce large amounts of a new variety in a relatively short span of time and thus intensifying the selection process. Breeding and selection is becoming increasingly more important, thus for Preesman a reason to invest in a new selection area with modern facilities. All these efforts resulted in a range of new varieties showing the Gerbera growers:
| An exceptional flower and stem quality, to guarantee maximum user satisfaction. | |
| A high production of flowers with special emphasis on the so-called "winter production". |
For the Australian and New Zealand market, Job Roskam from Roskam Young Plants Pty Ltd made a list of varieties which are suitable for the Australian and New Zealand growing conditions.
We, from Preesman B.V., and Roskam Young plants Pty Ltd, would like to help Gerbera growers to make the cultivars selected by them into a successful crop. Our experience in different production areas all over the world, guarantees a well-founded advice for your own special conditions.
For multiplication of our Gerbera selection, Preesman has its own tissue culture laboratory facilities. This well-equipped research complex and a competent staff of scientifically trained personnel will allow Preesman to further its knowledge on Gerbera's and if necessary improve multiplication methods. It also guarantees delivery of high quality plants.
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Cosmo |
Daikan (new) |
Deep Purple |
Divine |

2. Growth of Gerbera.
2.1 Plant system:
Gerbera's are mainly planted on a bench system. The space required between the walking paths is 75-80 cm. And the recommended distance between rows is 75-80 cm. The distance between the plants within the row should be 20 cm. The size of the distance between the plants is measured from heart to heart of the pot centre. A pot size of 3.5 / 4.5 litre and 18-20 cm deep is recommended.

2.2
Installing of the system
Before the system can be installed, the soil has to be levelled. Further, a
gutter has to be installed under the pots in order to collect the drain water.
In this way the ground under the bench system stays dry and the chance on
Botrytis is therefore reduced to a minimum.
This system provides the following advantages:
· The leaves can be bent, thus allowing the crop to become more open.
· It will improve the ventilation between the plants.
· It is easier to work while picking the flowers, or do crop maintenance.
· The (chemical) crop protection can be executed more efficient.
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Dubai (new) |
Easy Lover |
Fabio Orange |
Fana (new) |

2.3 Disinfection:
Take the following steps before planting;
| Clean the ground and bench system so there is no old plant materials left in the greenhouse. | |
| Disinfect the bench system, drippers and the pots with a disinfection material. |
2.4 Preparation of the soil.
To achieve the best result in growth of the plants, soil preparation before planting is required. Most of the growers in Australia have worked with a bark mix in the past, but more and more growers change to a coco peat mix to fill there pots. As it is important to have a good water / air balance, for the coco peat a mix with 20 - 40% perlite is recommended. The pot must be filled 100% with the potting mix.
3. Young plants.
3.1 Deflasking.
In the programme for Australia we can offer rooted plants delivered by Roskam Young Plants Pty Ltd, who work in cooperation with Clarinda Flower Farm Pty Ltd in Heatherton, Victoria. The propagation nursery has a computer controlled temperature, humidity, shade growing area. We use Fertil pots for the propagation of our gerbera plants, and there are 84 plants in a tray.
3.2 Ready-to-plant
The already rooted gerbera plants need no further cultivation. Plant them direct into the glasshouse upon arrival. To avoid any delay in transport, and quality loss, it is important to keep in contact with Roskam Young Plants Pty Ltd. Job Roskam will inform you about time of departure and expected time of arrival of the plants.
4. Planting.
Planting should be done in uniformly moistened potting mix. Place the plant into the potting mix so the top of the Fertil pot is 2 cm higher than the potting mix. If planted too high, the plants might break at harvest. While planting too deep increases the risk of disease (rotting of the heart). Prevent root damage by carefully pressing the potting mix against the pot. Under conditions with high daytime temperatures in the greenhouse (> 30°C), it is recommended to plant early in the morning or in the evening when the temperature are less extreme. To allow a good contact between pot and soil, it is recommended hand water very soon after planting.
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Full Moon |
Ice Queen |
Indian Red |
Jaffana (new) |

5. Water supply.
5.1 Drip irrigation.
A drip irrigation system is recommended; as each plant receives the same amount of water, and by supplying the water directly on the potting mix, the plant itself does not become wet (so preventing diseases). The pipes of the system are placed on the ground between the two rows, to prevent the dripper line becoming empty, and the water temperature in the dripper line is out the reach of direct sunlight.
5.2 Watering, how and when.
Start with irrigation about one or two days before planting, to make the potting mix already wet. This will help the gerbera plant to make a better start.
Start one hour after sunrise when the plants are just planted in the pots. In the first 1-2 months you must be careful that the potting mix does not get too wet, in this period you could stop 5-6 hours before sunset. When the plants are full grown you could stop 3-4 hours before sunset,
Use the drip irrigation 2-10 times a day. This depends on the size of the plant and the time of the year. There could be a difference, between a cloudy and sunny day of 40-50% in the usage of water with the gerbera plants.
The drain must be between the 30-40% of the total water gift, please note that there could be a difference between the structures of the soil, these means that every type of soil requires a different amount of water.
Per dripper a minimum of 60cc and maximum of 100cc should be give per irrigation. When the plants are older a minimum of 80cc per irrigation should be given depending on the season.
Check regularly if the moisture of the column just below the drip is the same as at the base of the column. If the top soil is wetter than the soil at the base, increase the water quantity per supply. On the other hand, if the situation is reverse (top soil drier than base), reduce the water gift.
5.3 Drippers
A
capacity of 2 litres per hour is preferred as the chance of congestion is
smaller.
By using a drip system, a
wet (water) column is created through which the roots grow.
Place the drippers by planting in the Fertil pot, after 2-3 weeks when the roots are growing out of the Fertil pot in to the potting soil replace them approximately 5 cm from the Fertil pot.
6. Screens;
One of the elements that attributes to optimum growing conditions in greenhouses are movable aluminized climate control screens. Such screens are used for different purposes, all linked to the growing climate: shading, cooling, temperature and humidity control. Besides this screens save on heating expenses. Short stems and a pale floral colour might be caused by too much sunlight and / or high temperatures. Shading will be the best solution.
7. Heating.
7.1 Temperature settings.
A gerbera plant requires in most of the parts of Australia heating, the ideal temperature for a gerbera is night time 15-16 degrees. The absolute minimum for the night is 12-13 degrees, if the greenhouse temperature becomes below this temperature the gerbera plant will show the following effects (shorter stems, colour of flower change, and more chance of botrytis) The day temperature should be at least 17-18 degrees, .
Prevent condensation on the flowers; it increases the problems with Botrytis on the petals (flowers). Avoid a rapid temperature rise, this causes condensation. If a heating system is available, raise the glasshouse temperature several degrees about four hours before sunrise. Start ventilation as soon as the sun starts influencing the glasshouse temperature.
With dark and rainy days it is better to put a minimum temperature of 40 degrees in the heating pipe, this will activate the plant and reduce the change of botrytis.
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Leonie |
Lieke (new) |
Lion (new) |
Madagascar (new) |

8. Fertilization.
A feeding unit with an A + B tank is preferred to give the exact quantity of nutrients to the plants. The EC and the pH are measured and directly corrected. The set points of the pH and EC put in the computer are given to the plants.
8.1 Fertilizer program:
(Note: this
fertilizer program gives an indication of what you could use, the fertilizer
solution could change because of the type of water and how the plants are
growing.)
Tank: A = 1000 Litre
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Calcium Nitrate |
CaNo3 |
26%CaO + 15.5 N |
75 |
Kg |
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Ammonium Nitrate |
NH4NO3 |
9%NO3 + 9% NH4 |
0-3 * |
Kg |
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Iron Chelate |
Fe |
Edta 13% or Eddha ** 6 % |
2 4 |
Kg Kg |
Tank: B = 1000 litre
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Mono Potassium Phosphate |
H2PO4 |
52% p2O5 + 34% K2O |
17 |
Kg |
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Potassium Nitrate |
KNO3 |
13% N + 46% K2O |
35 |
Kg |
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Potassium Sulphate |
K2SO4 |
52% K2O + 16% MgO |
2.5 |
Kg |
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Epson Salt (Magnan Sulphate) |
MgSO4 |
49%MgSO4 = 16% Mg0 |
25 |
Kg |
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Nitric Acid |
HNO3 |
38% |
0-10 *** |
Litre |
Trace elements:
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Manganese Sulphate |
Mn |
32% Mn |
70 |
Gram |
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Borax |
B |
11% B |
250 |
Gram |
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Zinc Sulphate |
Zn |
23% Zn |
125 |
Gram |
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Copper Sulphate |
Cu |
25% Cu |
25 |
Gram |
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Sodium Molybdate |
Mo |
40% Mo |
25 |
Gram |
* This
depends of the PH of your drainwater, if drainwater PH below 5.5 no
Ammonium Nitrate in the solution.
** When the PH from the drainwater is above the 6.5, you have to use EDDHA
iron.
*** This depends on the PH of the type of water you use e.g., rain, dam, bore
water.
8.2 Optimum EC
& PH;
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Water gift to the plants |
E.C. 1.6 - 1.8 |
PH 5.5 – 5.7 |
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Drain water if collect |
E.C 1.8 – 2.0 |
PH 5.2 – 5.8 |
8.3. NUTRIENT DEFICIENCY SYMPTOMS.
If mineral elements are not present in the medium in quantities sufficient for plant growth, plants exhibit nutrient deficiency symptoms. Anything that interferes with the active absorption of nutrient ions by the root system, likes unfavourable pH levels, or media temperatures significantly above or below optimum (15-25 degrees) may also result in similar symptoms. Root injury caused by root rots, water logging and inadequate aeration. Some of the visible deficiency symptoms of the different essential mineral elements are described below.
a. Nitrogen; Nitrogen deficiencies are rarely seen in commercial gerbera production. However, they can occur when growing media with low cation exchange capacities are used and over watering occurs. Nitrogen deficiency shows as a general overall yellowing or chlorosis, starting on the oldest leaves and then moving gradually upward. The progression of the chlorosis is from yellow-green to yellow to a creamy white. Because nitrogen is translocated out of the older leaves to the new growth under deficiency conditions, the youngest leaves rarely show any significant yellowing.
b. Potassium; Potassium deficiency first begins as a rusty brown, marginal necrosis of the older leaves. The centres of the leaf blades usually remain green, although some necrotic spots might occur. Severely affected leaf margins usually curl upward.
c. Phosphorus; Symptoms begin as a gradual brownish discoloration on the underside of older leaves, especially along the veins. Phosphorus deficiency symptoms usually occur during winter when soil temperatures are cold, and disappear when warmer weather returns.
d. Calcium; Calcium deficiency appears initially as death of the apical meristem (growing points), and sometimes as an extreme yellowing of the young developing leaves. The young leaves remain small and yellow, with colour turning gradually to a whitish yellow or creamy white. Edges of leaves eventually die and turn brown.
e. Magnesium; Magnesium deficiency is common on gerberas, due to insufficient amounts of magnesium in the growing medium and the lack of magnesium in most fertilization programs. The symptoms appear on the older leaves as an interveinal chlorosis, with a persistent, inverted, V -shaped green area remaining at the leaf bases. A V-shaped green area also persists at the leaf terminal. Once symptoms develop, they cannot be reversed.
f. Iron; Iron deficiency symptoms occur as an interveinal chlorosis, primarily on the younger leaves. The veins and veinlets remain as thin green lines. Leaves become progressively smaller, and the chlorotic areas ultimately progress from yellow to creamy white. In the last stage, even the veins and veinlets become chlorotic.
g. Zinc; Zinc deficient younger leaves are splotchy and chlorotic in colour, but the definitive symptom is that one half of the leaf blade ceases to expand and develop, while the other half is normal in size and shape. This uneven development causes the leaf to bend into a "C" shape.
h. Molybdenum; This deficiency is most prevalent in strongly acid («pH 5) growing media, and is displayed as "strapped" leaves, i.e. the leaves become exceedingly narrow, and the veins run parallel and overgrow at the margins to give ser- rated leaf edges.
I. Manganese; Manganese deficiency symptoms appear first on young leaves and are similar to those caused by iron deficiency, except that the persistent bands of green along veins and veinlets are broader, extending slightly out into the tissue to the leaf blade. The interveinal chlorosis is not as severe as with iron deficiency
Please note; When you use the above fertilizer mix, and the drip and drain EC & PH are between the indicate optimum (see 7.2), the chance to get some nutrient deficiency is minimal. So it’s very important to check the EC & PH a few times a week, and make adjustments when this is different than the indicate optimum.
9. Greenhouse climate.
As the conditions outside have a major influence on the climate inside the glasshouse, we can only give some general advice and remarks:
· In the initial period after planting, when light is a minor growing factor, shading of the glasshouse is recommended;
· Prevent direct wind. Gerbera's are not partial to windy circumstances. In the initial period after planting, keep the humidity as high as possible;
· As the plants are developing, the light intensity and ventilation of the glasshouse may increase. The plants themselves will have a major influence on the glasshouse climate by now (microclimate);
· Moistening of the plants is not advisable, so leaf wetness should be avoided;
· Prevent condensation on the flowers; it increases the problems with Botrytis on the petals (flowers). When this occurs, fungicides are of less use. Avoid a rapid temperature rise, this causes condensation. If a heating system is available, raise the glasshouse temperature several degrees about four hours before sunrise. Start ventilation as soon as the sun starts influencing the glasshouse temperature;
· To prevent Botrytis, a heating system could be used. The crop is kept dry by heating water at ± 45 °C through a heating pipe between the rows.
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Mette |
Pound Sterling |
Queen Victoria |
Rich (new) |

10. Crop maintenance.
Growing Gerbera's is rather straight forward, however picking leaves is often debated. Leaves, besides allowing photosynthesis, also reduce temperature and increase humidity, and therefore are an essential part of the plant. However, if the plants do become too bushy, it is recommended to remove only a few leaves at regular intervals Do not take away too many leaves at once!.
You can pull the leaves from the plant (natural breaking point), or cut them off leaving half of the leaf still standing.
After de-leaving it is advised to spray for Botrytis, this will kill the spores of the botrytis.
N.B. While pulling the leaves, be careful not to break the plant or damage young buds.
11. Harvesting of the flowers.
11.1 Picking the flowers
Depending on the conditions, a Gerbera starts flowering 8-12 weeks after planting. Harvest 2 to 3 times a week, however to get a uniform product some cultivars are recommended to be harvested at least 3 times a week by warm weather.
11.2 Target figures production per M2 & labour use per M2;
Production per m2 per year;
Holland ; Standard 230 / 250 stems per M2, Mini’s 450 / 550 stems per
M2.
Australia ; Standard 180 / 250 stems per M2, Mini’s 400 / 550 stems per
M2.
New Zealand ; Standard 180 / 250 stems per M2, Mini’s 400 / 500 stems per M2.
*** This figures are based on a 2 year crop production include the change of new plants.
Labour use per m2 per year
(indication);
Holland +/- 1.0 / 1.2
hour per M2
Australia +/- 1.5 / 2.0 hour per M2
New Zealand 1.5 / 2.5 hour per M2
Labour issues, registration;
There could be a lot
money saved on labour when the way of picking and packaging are done more
efficient. Most of the growers in Australia and New Zealand don’t knows exactly
how much time and money is spend on processing of the flowers.
The labour cost are rising and the production increase each year a few precent,
if noting is done the labour cost get to high percentage of the cost and it
would be harder to make a profit.
**** My suggestion is to start to count the gerbera production per M2 per week /
month, and also how much flowers are processed per hour. By doing this over a
longer period you could find out the progress over the years.
11.3 Treatment after picking the flowers
12. Diseases and pests treatment.
This is an international pest control list for Gerberas. Because of government regulation some of these chemicals may not be available or are not allowed in Australia and New Zealand. And we strongly recommend doing at least trials with the chemicals you have not used before, this to find out if you get any damage on the plants or flowers.
White fly:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
Broad Mite:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
Thrips:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
Red Spider:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
Aphids:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
Powdery Mildew:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
White rust:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
Sciarids / Fungesnads:
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Trade name |
Active ingredient |
How to use |
*****Contact us by e-mail, so we could send you a list of chemicals.
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