Growing Annuals

Course CodeBHT319
Fee CodeS2
Duration (approx)100 hours
QualificationStatement of Attainment

Become an Annuals Expert!

Who should study this course?

  • Nurserypersons, garden centre staff, gardeners, landscapers who grow annuals
  • Cut flower farmers
  • Seed producers, merchants and breeders
  • Anyone else with a passion for annual flowering plants

This eight lesson course reveals the secrets of how to identify annual species, what to grow and when to grow each variety. It covers soil improvement, pest control, irrigation, propagation, greenhouse growing, hydroponics and much more. It is equally as useful to the home gardener and to the professional gardener as to those intending to grow annuals commercially.

Lesson Structure

There are 8 lessons in this course:

  1. Introduction
    • Review of the system of plant identification, physiology, information sources
  2. Culture
    • This is a larger than average lesson; providing a fundamental understanding of what is needed to make annuals grow well.
    • Learn about Soils, pH, nutrition and fertilizers.; then move on to preparing a garden for planting, planting techniques, and caring for plants as they grow (eg. watering etc).
    • These things all underpin good growth.
  3. Propagation
    • Methods of propagating annuals,both sexual and asexual.
    • Emphasis on seed propagation, given this is the main way of growing annuals.
    • Propagation media, sowing seeds, potting up.
    • Collecting and storing seed.
    • Hybrid seed production.
    • Propagation of selected varieties of annuals.
  4. Growing Annuals in Hydroponics.
    • Hydroponics is used commercially and by hobbyists to grow certain annuals, mostly as cut flowers.
    • Learn how to grow hydroponically, different systems and techniques.
    • Growing Snapdragons, Carnations, Asters, Chrysanthemums, Gerberas and more in hydroponics.
  5. Pest and Disease
    • Distinguishing between diseases, pests, nutritional and environmental problems
    • Understanding significant problems and their control
    • Review a range of annuals not covered in other lessons.
  6. Irrigation
    • When, why and How to Irrigate
    • Symptoms of water deficiency or excess
    • Estimating water requirements
    • Types of irrigation and timing Irrigation
    • Distances between Sprinklers
    • Review a range of annuals not covered in other lessons.
  7. Greenhouses and Flower Beds
    • Annuals are grown both inside greenhouses and outside in flower beds.
    • See how to use a greenhouse to raise seedlings (for later transplanting outdoors); or growing either cut flower crops; or potted colour (for nursery sales), inside the greenhouse
    • Shade houses, benches
    • Environmental control
    • Managing plants and plant health
    • Flower Bed Design
    • Judging Flower Quality
    • Review a range of annuals not covered in other lessons.
  8. Harvest, Post Harvest & Quality.
    • Harvesting flowers
    • Post harvest physiology
    • Managing the Shelf life of flowers after harvest
    • Packaging cut flowers
    • Harvesting requirements for a range of different annual flower species
    • Review a range of annuals not covered in other lessons.

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.


  • Discuss the classification of annual flowering plants through the plant naming system.
  • Discuss culture requirements of annuals.
  • Propagate annuals.
  • Explain methods of hydroponic culture in relation to annuals
  • Identify pest and diseases of annuals
  • Describe various types of irrigation systems and the water requirements of annuals.
  • Describe various greenhouses and related equipment available.
  • Determine procedures for the handling of annuals during and after harvest.
  • Design annual flower beds.

Growing Annuals

Annuals are plants which are able to grow from a seed to a mature plant, flower, and produce seed all within the space of one year. They are grown widely around the world, in home gardens, public parks and other places - primarily because they can provide a quick and spectacular and often colourful display. Annuals are not usually the cheapest way of planting an area but nevertheless their potential to impress, ensures they will always have a place in horticulture.

The major advantages of annuals are:

  • They produce flowers quickly
  • They can be changed frequently

Annuals are grown both as commercial cut flower crops and as bedding plants (bedding plants are plants grown in a garden bed on a temporary basis).

Commonly grown annuals which are able to be used as both bedding plants and cut flowers include: marigolds, asters, stock, poppy, statice, calendula, gypsophila and helichrysum.  The range of plants grown as annuals goes well beyond this though. Consider the following, just to begin with:

Low Growing Annuals (less than 30cm)
• Ageratum
• Alyssum
• Antirrhinum (small type)
• Aster (dwarf types)
• Begonia (dwarf bedding types)
• Bellis (English daisy)
• Brachycome
• Calceolaria (slipper flower)
• Cineraria (dwarf types)
• Dianthus (pinks)
• Impatiens (busy lizzie)
• Linaria
• Lobelia
• Matthiola (stock dwarf types)
• Matricaria (feverfew)
• Mesembryanthemum (livingstone daisy)
• Mimulus (monkey flower)
• Myosotis (forget me not)
• Nemesia (dwarf types)
• Nemophila (blue eyes)
• Nigella (dwarf types)
• Petunia
• Phlox (annual phlox)
• Portulaca (sun plant)
• Verbena
• Viola (pansy, viola)
• Zinnia (dwarf types)

Medium Height Annuals (30 60cm)
• Acroclinum (everlasting daisy)
• Antirrhinum (medium types)
• Arctotis
• Begonia (bedding type)
• Calendula
• Campanula
• Celosia
• Centaurea (cornflower)
• Cheiranthus(wallflower)
• Chrysanthemum
• Clarkia
• Coreopsis
• Cosmos (some)
• Dahlia (bedding type)
• Dimorphotheca
• Gaillardia (blanket flower)
• Godetia
• Gypsophila (babys breath)
• Helichrysum (straw flower)
• Heliotropium (heliotrope)
• Iberis (candytuft)
• Limonium (statice)
• Matthiola (stocks)
• Nemesia
• Nigella (love in a mist)
• Papaver (poppy medium types)
• Phlox (taller types)
• Rudbeckia
• Salvia
• Schizanthus (poor mans orchid)
• Tagetes (marigold smaller and medium types)
• Tropaeolum (Nasturtium medium types)
• Zinnia

Tall growing Annuals (greater than 60 cm)
• Althaea (hollyhock)
• Amaranthus
• Antirrihnum (snapdragon tall types)
• Cleome (spider flower)
• Cosmos (tall types)
• Helianthus (sunflower)
• Helichrysum (strawflower tall types)
• Lathyrus (sweet pea)
• Lunaria (honesty)
• Molucella (bells of Ireland)
• Papaver (poppy tall types)
• Rudbeckia (tall types)
• Scabiosa
• Tagetes (marigolds tall types)
• Tropaeolum (nasturtium tall types)

Grow an Annual Flower Bed

Nothing beats annual flowers for a fast, brilliant display of colour in the garden. There are varieties for all times of the year, and all climates; and you can achieve a colourful display within as little as a few weeks from planting, with the right treatment.
Why People Grow Flower Beds
  • Plants flower faster and reach full size faster
  • Many more plants per dollar
  • Greater % of plants likely to survive
  • Sometimes greater satisfaction, and instant gratification
  • You get to keep reinventing what the garden looks like
 The Down Side
  • Plants are not as permanent
  • Plants tend to be more prone to extreme conditions (e.g.dramatic drops or increases in temperature)
  • More work - you need to keep replacing plants
Raising Annual Seedlings in Winter
Seeds can be planted directly into the soil or germinated in a container, and grown a little before planting out. When you raise seeds in a pot or tray, you have the advantage of being able to bring them inside (e.g. into the bathroom, kitchen, laundry or greenhouse) where the warmer conditions will help seed germinate and grow faster. They can then be taken from the germination container and planted straight into the ground – or if you prefer, put into a bigger pot.
When seedlings are planted out, they often suffer 'transplant shock' which can cause a severe setback to growth, and possibly death. Prior to transplanting give them a good soaking with a seaweed solution – this reportedly assists seedlings in overcoming transplant shock.
When transplanting, leave as much soil around the roots of the seedling as you can and don’t leave roots exposed to the air for any time at all if possible. After transplanting, water them well with a weak liquid fertiliser (too strong will burn). 
If you plant seeds outside now, cover them with a cloche or cold frame to give them a head start on spring.
Soil, Water and Pest Control are Critical
Annual flower seedlings grow and mature very quickly. Their tissues are tender and more susceptible to pest and disease attack than most woody plants. If the soil is good, water ample and growth vigorous, most problems simply won’t get a grip on the plants; but if conditions are poor, their susceptibility to pest and disease attack is high.
Plant Now for a Future Event
Do you have a birthday, family gathering, wedding or any other event happening at home in a few months time? Plant annuals now and stun your visitors with a blaze of colour.
The trick is to get the right plants for the time of year. This is where your garden centre staff can be very helpful. Don’t be afraid to ask for their advice. They know the local conditions, what flowers when, and when you need to plant for the effect you are after.


How To Use Annuals

  • For a great effect plant annuals in massed displays or in small groups or drifts: massed plantings – plant one variety for a stunning display, or plant a mixture for a less formal appearance.
  • Don’t overdo massed plantings – too many can look monotonous, gaudy, or overly formal.
  • Ribbon or drift plantings – plant the same variety in a ribbon or in groups at repeated intervals to give a feeling of repetition and continuity.
  • Edge plantings – plant low-growing annuals along the edges of garden beds and paths to give a neat, colourful border.
  • Dot plantings – plant small groups (usually three to five plants) of the same medium to tall varieties to act as focal points in mixed beds. 
Other ways to use annuals:
  • As fast-growing fillers, for covering up bare spots in the garden
  • As foliage contrasts in mixed beds
  • In hanging baskets, pots and window boxes  
In larger beds, annuals can be planted according to height, with the low varieties on the outside and taller plants in the centre: 
  • Low plants to 15 cm, eg. Alyssum, Ageratum, Lobelia, Viola, Verbena. 
  • Medium plants 15–70 cm, eg. Zinnia, Bedding Dahlia, Salvia, Antirrhinum
  • Tall plants over 70 cm, eg. Amaranthus, Cosmos, Hollyhocks, Sunflowers


  • Nurserypersons, garden centre staff, gardeners, landscapers
  • Cut flower farmers
  • Seed producers, merchants and breeders
  • Anyone else with a passion for annual flowering plants

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