If you want a garden that looks established quickly, you either need to plant big plants; or use plants that grow very fast. The problem with planting large plants is that they may not ever be as healthy, as they might have been if they were grown from earlier on in their final location. Transplant shock can always damage or kill big plants more than smaller ones.
In a temperate climate most trees and shrubs will take at least a few years from planting to fill out and make a garden look established.
In a tropical climate this can be a lot faster, but with the right plant choices, in any climate, a garden can look established in perhaps a third of the time.
WHAT AFFECTS GROWTH RATE?
Climate, soil, water, nutrition, even pests/diseases will affect a plant’s growth rate. To encourage optimum growth, all plants (even naturally fast-growing plants) benefit from extra care. For most plants this means:
planting in a sheltered position, away from wind and frost
planting in well-drained soil that has been enriched with organic matter
giving adequate water and fertiliser
mulching to keep the soil moist and to prevent competition from weeds
controlling pests and diseases
regular dead heading (removing dead flowers before they set seed)
Some plants grow like a rocket in one location, but are very slow in another, so you need to match the variety to the location.
Plant variety is also very important in determining growth rate. Tall herbaceous perennials grow faster
Timing can be important…plant out in spring when the air and soil temperatures are warming up rather than late autumn if you want the fastest growth. In many areas during spring, the soil is still moist after the winter rains and this also helps the roots to quickly establish in the soil.
Cutting the plant back after flowering helps promote new vigorous growth. Prune the plant back by around 1/3, and remove any old, diseased or unproductive wood. Also remove the flowers regularly as these use up the plant’s energy as they develop into seeds. This is known as “dead heading”.
Some Fast-growing Plants
(Note: speed of growth may vary according to the climate, water & soil conditions)
Trees and Tall Shrubs
Acacia spp. (most wattles)
Angel’s Trumpet (Brugsmania suaveolens)
Butterfly Bush (Buddleia)
Geraniums & Pelargoniums
Scaevola Mauve Clusters
Grevillea ‘Royal Mantle
In the right conditions, most herbaceous perennials and herbs are relatively fast growing; including impatiens, coreopsis, lavender, gazania, etc.
Some Plants Grow hard and fast – and die young
Before you plant a fast-growing tree, check its life span.
Some fast growers such as Acacias (Wattle Trees) grow rapidly but may only live for 3 or 4 years (maybe even less). While they’re great for short-term screens or windbreaks, they won’t last long – usually because they have shallow roots and brittle stems which are easily blown over or damaged in storms, or because they are decimated by borers or other insects.
A dying or dead tree can be dangerous, difficult and expensive to remove, so think twice about whether it’s the right plant for your position.
Colourful, Tall and Fast
Many herbaceous plants that can grow over 1 m tall in a matter of months, for example Sunflower, Dahlia, Russell Lupins and some grasses.
The only drawback is that some only last for one season, while others die down during for part of the year.
Grow a fast climber on a trellis for a quicker height and mass of green. Fast growing climbers include Jasmine, Honeysuckle, Potato Vine
There are species of the following that grow very fast; but you need to get the appropriate species for your location: Acacias (Wattle trees); Eucalyptus (Gum trees);
Some More Tips
Paulownia is a fast growing species perfect for a warm climate.
Salix babylonica or willow tree can be quick growing on wet soils, in temperate climates.
Populus or poplars give fantastic autumn colours and are quick growing
Many succulents such as this Crassula arborescens are such fast growers that they are invasive weeds in some areas.
Wildflowers (annuals) are quick and colourful. Annuals are designed to grow to full size and flower in a matter of months. If you choose the right varieties for the time of year and location, you can achieve an almost instant garden.
Wattles (and other legumes) such as this Acacia dealbata have a unique and wonderful ability to obtain plant nutrients not only from the soil, but also indirectly from the air. This often allows rapid growth in even the poorest soils.
Gum trees such as this Eucalyptus ovata are generally fast growers, although there are exceptions. It all depends on the variety, your soil type and how you treat the plant. Always ask for some advice from your nurseryman (who should have valuable local knowledge)
Melaleucas such as this Melaleuca elliptica and Callistemons, both produce masses of attractive bottlebrush like flowers. Most varieties of both will grow fast in all but the poorest conditions.
Large grasses including Bamboos and Cortaderia (Pampas Grasses) such as this Cortaderia fluvida are very fast growing; but can become invasive and troublesome weeds in some areas. In the right position Pampas grasses can look great. In the wrong position, it is irresponsible and may even be illegal to grow it.
Tecoma capensis is fast growing in both temperate and tropical climates. In some warmer localities though, it will self seed and can become a serious weed problem.
Lupins & Hollyhocks are both very fast growing, tall perennials; provided soil, water and other conditions are good.
Bougainvilleas grow like wildfire in warmer climates. Some varieties are also fast if planted in a protected but sunny position in southern Australia.