TROPICAL PLANTS BHT234

Distance Education Course:  Become a Tropical Plants Expert

• Learn to identify and grow different tropical plants
• Learn to use tropical plants in gardens, as indoor plants, container specimens, etc.
• Follow your passion, or work with tropical plants as a career
• A course for nurserymen, plant breeders, landscapers, gardeners, interior plantscapers, or anyone with an enthusiasm for tropicals.
  

Tips for Growing and Using Tropical Plants

Lush growth, vivid colours and a warmth in the air which makes anyone feel relaxed; these are what we strive for in a tropical garden. All too often though, we get uncomfortable sweltering heat, wilting plants and armies of insects that eat the garden faster than it grows. This book shows you how to get closer to the first of these options, and ways of overcoming those problems which are particular to gardens in warm climates.

TROPICAL AND SUB TROPICAL GARDENS

Before reading any further, you should decide what you want a garden for. Some people have a dream, an image of an "oasis" to escape the heat, or the problems of daily life. Others want a garden they can use, for entertaining, outdoor living, for children to play in or maybe even a place to keep a prized collection of plants. Whatever your purpose, it is important to plan. Planning never stops either, because a garden never stands still. Try to foresee what will happen in your garden in the future (eg. trees and shrubs which will die, areas that will gradually become more shaded), and plan changes to your garden accordingly.

TYPES OF GARDENS AND PLANTS

There are many different types of gardens. You might choose to have any of the following; or perhaps a garden which has aspects of more than one type.

FORMAL OR INFORMAL

Formal gardens are neat and tidy, the edges of paths and garden beds are usually very well defined, and the garden is often a symmetrical design (ie. one part of the garden is a mirror image of an adjacent part). Shrubs are often clipped to develop a specific shape as a hedge or trained against a wall.

Informal gardens are not always so neat, edges are often irregular shapes with plants spilling from beds onto lawns or paths. The overall affect is less manicured and if designed properly things do not look so unattractive or out of place even when maintenance is neglected for a period.

Gardens can have varying degrees of formality. Generally the most formal gardens are the most time consuming to maintain.

BUSH GARDENS

These try to recreate a natural environment. It is important that you choose a theme and stick to it otherwise the garden may look quite nice but be a meaningless assortment of plants. Many of the best native gardens are modelled on real bush examples (eg. An open woodland, a dense forest, rainforest, heathland or rockery).

DRY GARDENS (Xeriscapes)

A xeriscape is a garden which is developed for harsh dry conditions. It uses plants which tolerate drought and heat. (eg. Cactus and succulent garden, Desert garden, Australian Native Arid Zone Garden).

ORGANIC GARDENS

This is a garden which uses only natural materials in it's creation and maintenance. It is free of pesticides and artificial chemicals. Mulch and compost are used to feed plants, smother weeds and reduce the need for watering. Other natural techniques are used to minimize pests and diseases. Those problems which occur beyond this are simply tolerated in the knowledge that nature will eventually re-establish a balance.

PERMACULTURE

Permaculture gardens are designed to produce things which can be used (eg. food, crafts, fuel, etc), and to create an environment which is protected from undesirable affects of nature (eg. extreme wind, heat, flood, etc). It doesn't really matter what a permaculture garden looks like, as long as it is functional, environmentally friendly and relatively low maintenance.

COTTAGE GARDENS

Cottage gardens originated in temperate climates, but the style has evolved and been adapted successfully in hotter places. These are low maintenance gardens, which mix a wide variety of flowers and other useful plants (including fruit and vegetables), creating a montage of colours and textures. They usually contain little or no lawn, lots of colour, a large variety of textures and colours, edible and scented plants, and a variety of traditional features such as trellis, wrought iron, picket fencing, cast iron furniture, statues, topiary, low hedges, sundials and birdbaths.

COMPANION PLANTING

Companion planting is based on the idea that certain plants grow better in close proximity to other plants. (eg: Garlic planted under a peach tree will improve the performance of the peach by deterring the development of peach leaf curl, a disease which is very common on peaches). Companion planting works by using plants which either deter pests or disease, attract pests away from valuable plants, or contribute to the fertility and structure of the soil.

SPIRALS

A spiral garden is a raised or sunken garden where the plantings form a spiral either rising up the mound or sinking into the depression. The spiral is delineated by a wall (stone, timber, masonry) which both serves to retain the earth on the slope and also to separate one area of garden bed from the adjacent area (which is at a higher or lower level).

Water which falls onto the highest point of the spiral will always tend to run down hill (in a spiral), collecting at the lowest point. The highest part of a spiral garden is generally the driest (hence is planted with plants which prefer drier conditions). The lowest point of a spiral (particularly in a sunken garden) is the wettest (hence is planted with plants tolerant of wet conditions, or preferring wet soil).

NO DIG GARDENS

In simple language, this type of garden is made by making garden beds using deep compost heaps on top of the ground. Plants are then planted straight into the top of these mounds. As they slowly rot down the mounds release a constant supply of nutrients to feed plants, and being raised above ground level they provide good drainage while the organic matter still retains ample water for the roots.

ORIENTAL GARDEN

Japanese and Chinese gardens each have their own unique style, but both share similar principles. These gardens emphasise nature. Materials (plants, rocks, gravel, water etc) are used in a very natural way where harmony and tranquillity are primary aims. These gardens are much more common in cooler areas, but with a bit of perseverance, a garden with such a theme may be possible in the tropics.

MIDDLE EASTERN GARDEN

Typically formal and ornate, these gardens make extensive use of tiles and garden structures. Pergolas or other structures are often incorporated for shade, water is usually included for coolness, and the garden is often walled for security and privacy.

WALLED GARDEN

Walls create a sense of enclosure in a garden, and also create a protected environment, restricting air movement (ie. wind). In hot areas a walled garden may look great but must be designed carefully if it is to avoid becoming a heat trap.

WHAT IS SO UNIQUE ABOUT WARM CLIMATES

Warm climates all have one thing in common; they get hot during the day. Apart from this they can vary a great deal from place to place. There are places in the sub tropics which can record very cold temperatures at night (eg. Desert areas and high mountains); and there are places which are extremely dry as well as places which are very wet.

Generally light levels are higher, and day lengths don't shorten or lengthen to the same extremes that they do in cooler climates.  Wherever there is water in a hot climate, humidity can increase. Humidity can be good for some plants and bad for others; and will be greater in wet climates, after rainfall, near lakes and canals, in irrigated areas or around plants which are mulched with moist organic materials.  Storms can be more fierce in the tropics. Rain often falls heavier, winds blow stronger, and plants can be badly damaged by cyclonic conditions. Summer, Autumn, Winter and Spring don't seem so obvious in warmer climates. There are really only two, more obvious seasons: the wet and the dry. All of these factors can have serious affects upon the way some plants perform.

WHAT CAN YOU GROW EASILY?

The best way to know what grows well in your locality is to look around at other gardens in the area, and note what other people are growing most successfully.

Many plants grow much faster and easier in hot climates than in temperate areas; but often the diseases, pests and weeds will also develop faster. Some plants listed in this book can in some areas grow so well that they become invasive and turn into weeds. The easiest plants to grow are not always the most vigorous.

Remember vigorous plants may require frequent cutting back. Look for plants which are generally resistant to pests and diseases, tolerate adverse conditions, but do not grow so vigorously that they become invasive.

Lesson Structure

There are 10 lessons in this course:

1. Introduction to Tropical Plants
   • What does the term "tropical" mean
   • What tropicals grow where you live?
   • Plant names/classification (scientific & common)
   • Species, hybrids, varieties and cultivars
   • Growing Tropical Plants in different climates; tropical, sub tropical, arid and temperate
   • Climatic Variations; seasons, mountains, savannahs, rainforest, coastal
   • Gardening for Warm Climates and Microclimates
   • Good and Bad News about Tropical Gardening
   • Heat Traps, Warming a Garden, Greenhouses
2. Plant Cultural Practices
   • Common Gardening Problems
   • Understanding soils, naming a soil, texture, pH, fertility, nutrition, feeding
   • Water and Plant Growth
   • Water deficiency and excess symptoms
   • Water Dynamics in a Soil
   • Planting and Plant Establishment Methods
   • Light Requirements
   • Mulches
   • Tree Guards
   • Weeds
   • Propagation,cutting, seed, propagating media
   • Potting Mixes, Potting up, Caring for young plants
   • Pruning etc.
3. Tropical Annuals, Perennials, Bulbous Plants, Bamboos & Lawns
   • Bamboos, Grasses and Grass Like Plants
   • Landscaping with Bamboos
   • Review of Bamboo species
   • Review of other herbaceous tropicals, including: Achmines, Agapanthus, Alocasia, Amorphophallus,Aristea, Babiana, Boophone, Brunsvigia, Caladium, Calaqthea, Calostemma,Clivia, Calocasia, Crinum, Crocosmia, Cyrtanthus, Dierama, Eucharis, Eucomis, Gladiolus, Gloriosa, Zephranthes, Hippeastrum, Hymenocallis, and many others
   • Lawns
   • Turf Varieties for Warm and Hot Areas
4. Ornamental Gingers and Heliconias (and related plants)
   • Introduction
   • Zingerbales; Musaceae (bananas), Strelitziaceae (bird of paradise), Lowiaceae, Heliconiaceae (heliconias), Zingiberaceae (gingers), Costaceae (costus), Cannaceae (cannas), Marantaceae (prayer plants
   • Gingers
   • Heliconia
   • Costus
   • Canna
   • Strelitzia
5. Cordylines, Palms & Cycads
   • Types of Palms; self cleaning, cleaning, solitary or clumping, fan or pinnate, etc
   • Palm Propagation
   • Review of many cultivated Palm Genera
   • Cordylines
6. Climbers, Shrubs and Trees
   • Review of many cultivated Tree and Shrub Genera
   • Cultural Requirements
   • Review of many selected species characteristics
   • Conifers; culture, genera, species
   • Climbers; Allamanda, Antigonon, Aristolochia, Beaumontia, Bignonia, Bougainvillea, Campses, Ceropegia, Cissus, Clematis, Clerodendrum, Clitoria, Clytostoma, Combretum, Congea, Ficus, Hoya, Ipomea, Manettia, Mucuna, Pandorea, Philodendron, Scindapsis, Stephanotus, Thunbergia, Trachelospermum.
7. Orchids, Ferns, Aroids and Bromeliads
   • Orchid introduction
   • Growing Orchids
   • Epiphytes
   • Orchid Genera
   • Bromeliads
   • Growing Ferns
   • Types of Ferns; Fern Classification and families
   • Fern Culture
   • Aroids
8. Tropical Herbs, Vegetables and Fruit Bearing Plants
   • Growing Methods; organic, no dig, permaculture, Container Growing, Hydroponics, etc
   • Culture of Selected Vegetables in tropical and sub tropic conditions
   • Bush tucker
   • Tea and Coffee
   • Tropical Fruit trees
9. Growing Tropical Plants outside the Tropics
   • Growing tropicals indoors
   • Growing in different climates and conditions.
10. Landscaping with Tropical Plants
    • Use of colour & texture
    • Plant selection
    • Planting a courtyard
    • Preparing sketch plans.

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.

Aims

• Explain the nature and scope of tropical plants
• Discuss cultural characteristics that are often peculiar to tropical plants
• Describe the taxonomy and culture of a range of soft wooded tropical plants including annuals, perennials and bulbs.
• Describe the taxonomy and culture of Heliconias and Gingers..
• Describe the taxonomy and culture of Palms and Palm like tropicals.
• Describe the taxonomy and culture of climber, tree and shrub tropical plants.
• Describe the taxonomy and culture of Orchids, Ferns and Bromeliads.
• Describe the taxonomy and culture of Herbs, Vegetables and Fruits in tropical conditions.