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1. Proteas
2. Carnations


by staff of the Australian Correspondence Schools
E. Mail [email protected]

This article is under copyright, however, feel free to print and use it provided that the authorship is acknowledged.

By harvesting and handling a cut flower crop in the best way, you can improve quality of the marketable product, hence improve the potential profit from the crop.

Different types of plants need to be harvested differently, and treated differently after harvest. The time at which you harvest depends upon the stage of growth which the plants are at; but it can also be affected by market demand. (eg. You may decide to harvest plants before they reach an optimum stage because you can get more for the flowers at that earlier time when demand is higher).

Some flowers should be opened well before the buds open; and the buds then open later on. This makes transport easier, and sometimes means that the flowers last longer. For other flowers, the flower must be at least partially opened. It might not open if harvested too earlier. The grower needs to have a very good knowledge of how the flower continues to develop after harvest.

Buds are stimulated to open by different things. For many plants, heat will stimulate bud opening; so keeping the plant cool is important if you wish to delay bud opening.
Special solutions can be used to help regulate bud opening, extend the life of the flower and discourage disease attacking and rotting the stems. This is particularly important on some types of flowers when they are picked early. Carnations, among other things, are often treated this way. Solutions can be used to do the following:

  • Increase the number of flowers on stems harvested prematurely.
  • In cold storage, delay immature buds from opening for a short period until market demand increases.
  • To hold buds from opening until after a weekend when businesses are closed and selling isn't happening for a couple of days.

Solutions often contain sugars to compensate (partly) for inadequate food reserves available to the buds, and a sterilant such as sodium hypochlorite, to kill disease organisms in the water. The strength of chemicals used can be critical. Some flowers are damaged by concentrations which are ideal for others. (eg. Roses and chrysanthemums are susceptible to excessively high levels of sugar).
These solutions need appropriate temperatures to be absorbed by the plant. At very low temperatures they will not be absorbed, so cool stored plants may be sometimes put into a warmer situation for a period before cool storage to allow absorption.


Flowers sometimes need to be "hardened up" before packing and sending off to market. This may involve standing in "cold" water to allow turgidity to reach optimum level (ie. maximum amount of water in the plant tissue), before they are packed dry and sent to market. A solution containing a flower preservative and bacteriacide is often used in the water at this stage.

Flowers can be transported in dry or wet.
Dry transport means the stems are out of water.
Wet transport means the stems are standing in water.
The method used depends on the variety of plant, method of transport and duration of transpot. Dry transport may be in plastic or canvas slings, which individual blooms are placed ino on harvest. Wet transport may involve picking into canvas or plastic slings, or picking into buckets of water.
Either way, the flowers are placed in water soon after picking When harvesting, always have more slings and containers than you think will be needed. Overcrowding blooms makes separation and grading difficult later.

The time a flower can be stored varies greatly between varieties. Some orchid flowers can remain open for two months, but most flowers do not last so well. Flower quality begins to deteriorate as soon as it is harvested. Good storage slows deterioration, but does not stop it. Flowers cut in a warm place will have a lot of heat in the plant tissue, and unless cooled quickly, that heat will remain and continue to hasten deterioration. It is therefore essential to get the temperature of most flowers down to 10-15 degrees celsius as soon as possible after harvest. The best way to do this is to stand picked stems in deep, cold water.
Vase life is the length of time the flower will last in the vase after picking.
Vase life is affected by:

  • Humidity
  • Ventilation
  • Temperature immediately after harvest.
  • Storage temperature later on (for most flowers 2-5 degrees celsius is ideal, for some this is too cold).
  • Weight loss (through drying) after harvest.
  • Oxygen and carbon dioxide levels in storage
  • Exposure to disease
  • Ethylene (high levels decrease vase life). Ventilation -air movement -spacing between stems; is all important in preventing ethylene build up.
  • Air pressure (lower air pressure may help extend vase life) (NB: Some of these factors are interrelated)



The Certificate in Horticulture  providing specialised training for employment in the horticultural industry. There are two parts to this certificate:
A. CORE UNITS - to develop broad general skills in horticultural practices, and plant knowledge. All students undertaking this certificate will complete these units. The core units comprise approximately 50% of the course content.
The core units consist of the following lessons:
  1. Introduction To Plants
  2. Parts Of The Plant
  3. Plant Culture - Planting
  4. Plant Culture - Pruning
  5. Plant Culture - Irrigation & Machinery
  6. Soils & Media
  7. Soils & Nutrition
  8. Seeds & Cuttings
  9. Other Techniques
  10. I.D. & Use Of Plants - Landscape Application
  11. I.D. & Use Of Plants - Problems
  12. I.D. & Use Of Plants - Indoor & Tropical Plants
  13. Pests
  14. Diseases
  15. Weeds

B. STREAM UNITS - to develop specific skills in one specialised area of horticulture. This comprises the remainder (approximately 50%) of the course. Stream units are currently available in the following areas.
Choose "one" from the following list.
  • Organic Plant Growing
  • Permaculture
  • Ornamental Horticulture
  • Grounds Management
  • Turf
  • Nature Park Management
  • Arboriculture
  • Plant Protection
  • Propagation
  • Landscaping & Garden Design
  • Crops
  • Viticulture
  • Cut Flower Growing
  • Horticultural Technology
  • Herbs

Fee Code: CT plus exam fees covers all necessary costs.
Enrol online


Australian cut flower growing has experienced rapid expansion in recent years, resulting in increased demand for training in the skills and knowledge required by this industry. This course provides a thorough basic training for the commercial cut flower grower. There are twelve lessons as follows:
1. Introduction To Cut Flower Growing.
2. Culture - planting, watering, feeding, etc.
3. Flower Initiation & Development.
4. Pest & Disease Control.
5. Managing Yield & Greenhouse Operation.
6. Farm Management, Harvest & Postharvest.
7. Perennials - carnations, chrysanthemums, etc
8. Annuals - stock, helichrysums, etc.
9. Bulbs, Corms, Tubers & Rhizomes.
10. Fillers - ferns, gypsophila, etc.
11. Natives - Chamaelaucium, boronia, banksia, dryandra, etc.
12. Other Plants -Roses, orchids, proteas, etc.

Fee Code: S3
Enrol online


A course for the enthusiast or commercial bulb grower, with ten lessons as follows:
1. Introduction - Parts of the flower, understanding soils, hydroponics.
2. Cultural Practices - soils, planting, etc.
3. Flower Initiation & Development
4. Pest and Disease Control - Identification and control of common pests and diseases.
5. Managing Yield, Greenhouse Culture
6. Management, Harvest and Post-Harvest - Crop schedules, layout, marketing, etc.
7. Gladioli and Lilium.
8. Narcissus.
9. Iris.
10. Other Bulbs - Dahlia, Freesia, Hyacinth, Tulip, Alstroemeria, Amaryllis.

Fee Code: S3
Enrol online


A course for commercial cut flower growers who are concerned exclusively with greenhouse production. There are twelve lessons as follows:
1. Introduction.
2. Cultural Practices.
3. Flower Initiation And Development.
4. Pest & Disease Control in Greenhouses.
5. Greenhouse Management A.
6. Greenhouse Management B.
7. Management, Harvest & Post Harvest.
8. Herbaceous Perennials.
9. Annuals & Biennials.
10. Bulbs Corms & Tubers.
11. Filler Plants.
12. Roses, Orchids, etc.

Fee Code: S3
Enrol online


Learn how to produce orchid flowers for the cut flower trade with ten lessons as follows:
1. Introduction - Plant classification, naming of plants, parts of the flower.
2. Culture - Basket, epiphytes, media.
3. Propagation A - Methods, materials, equipment.
4. Propagation B (Tissue Culture) - Techniques, application, culture nutrients.
5. Greenhouse Management A - Environmental controls, beds & benches, carbon dioxide.
6. Greenhouse Management B - Temperature, irrigation, cooling, ventilation, etc.
7. Pest and Disease Control & Identification
8.. Management, Harvest and Post-Harvest - Harvesting, post harvest, standards, layout, production costs.
9. Marketing - Marketing the product, valuable orchids, international markets.
10. Detailed study of one species or group of orchids.

Fee Code: S3
Enrol online


First published in 1991, currently in its third reprint, this is a best seller both in Australia and overseas. It differs from most other hydroponic books in that it emphasises how to grow specific plant varieties, rather than the mechanics of how to set up a hydroponic system. The major systems which have been commercially successful throughout the world have been given significant attention, but less popular methods while mentioned, are not given significant attention in this book. Detailed information is supplied on 86 different types of plants, and how to grow them in hydroponics. These include vegetables, flowers, berries, herbs, indoor plants and other plants. The uniqueness of this "plant information", has made this book both popular and extremely valuable to both home gardeners and commercial growers.
194 pages
240 X 18 mm hardcover
Published by Kangaroo Press in Print
Published by ACS as an ebook
Available at