Bonsai basics: 4 essental rules

Bonsai are forever – or at least they should be. Diminutive forms of trees and shrubs, they can last just as long as their larger cousins planted in the garden, and bring you just as much delight over many, many years. Successful growing of bonsai comes down to a few simple rules of plant maintenance – follow these guidelines and your mini trees will be things of beauty forever.

Rule 1: Location
The first rule of growing bonsai is that you must keep them outdoors. They are definitely not indoor plants! Although you might have seen bonsai plants displayed indoors at garden shows, this is only for two or three days at a time. Think of your bonsai like any other potted tree or shrub, and position it in a protected outdoor spot which suits the preferences of the particular species. Plants such as conifers, figs and banksias will need full sun, while shade lovers like maples and azaleas will need a position with dappled light, or morning sun and afternoon shade.

Rule 2: Watering
With bonsai the general rule is that they must be kept moist at all times. It’s not a surprising requirement, considering that their intricate top growth is supported by such a shallow root system. And on the flip side, they must have perfect drainage, too, so that excess water escapes quickly, to avoid any chance of root rot. You’ll find that most good bonsai pots feature built-in feet to ensure that the water can escape with ease.

Summer
During constantly hot summer weather, mature bonsai plants will need to be watered every day – try watering them after you brush your teeth, so you don’t forget! If you live in a region with mild summer temperatures, watering three or four times per week should be adequate. If you are in doubt, check that the surface of the potting mix is moist. And if you encounter a serious heatwave, you should water the soil and spray the foliage to help your plant survive the onslaught.

Winter
Cut back on watering during winter, as the evaporation rate through both leaves and soil is much lower at this time of year. Watering your bonsai once or twice a week will usually be adequate, but be vigilant if the weather is windy, as this can dry the soil out quickly.

Rule 3: Feeding
When it comes to feeding bonsai, the basic rule is to go gently. Fertilising is only recommended when plants show signs of new growth, as the weather begins to warm up at the start of spring. For best results, apply a controlled-release fertiliser suitable for pot plants, which will feed the plant gradually over 3-6 months. To keep your bonsai plant in top form, you can also apply a seaweed-based food, such as Miracle Gro Seafeed 3 in 1, once every four weeks or so, from spring through to autumn.

Rule 4: Pruning
Pruning of branches is a very important part of the art of bonsai. During the dormant period in winter, evergreen and deciduous trees can be pruned heavily and unwanted branches removed, but all flowering trees should be pruned after flowering. During the growing season, occasionally pinch out new leaves with your fingers to keep the tree compact and in good shape. Keep in mind, pruning is best done on healthy trees.

Stockists: Amgrow Bonsai Potting Mix; scissors; tie-wire, Bunnings, www.bunnings.com.au Bonsai tools and equipment, Bonsai Art, (02) 9450 2802 or www.megumibennettbonsai.com

Bonsai rescue

To revive an ailing bonsai you need to give it a double-pruning, which means trimming the growth both above and below ground level. Late winter or early spring are the best pruning times. Here, our subject was a struggling buxus bonsai with an interesting history – it was the plant in the opening credits of the TV series Find My Family, but was accidentally cooked in a summer heatwave.

You’ll need
Sharp scissors; tie-wire; plastic mesh; bonsai potting fork; bag of bonsai potting mix; fine gravel.

Step 1
Immerse the pot in a bucket of water to thoroughly saturate the root zone and make it easier to remove the plant from its pot.

Step 2
To check which stems are dead, lightly scratch a small section of bark with your fingernail. If the wood beneath is hard and brown, rather than green and sappy, the branch is dead. Using scissors, remove all dead wood. Next, shorten back remaining green shoots by a few centimetres, to balance the shape of the plant.

Step 3
Using blunt end of bonsai fork (or a broad-bladed knife), loosen mix around edges of pot. When plant is loosened, lift, roots and all, out of pot. Using fork’s tines, rake soil to expose outer roots.

Step 4
Using scissors, prune around root ball of the plant, removing the ends of the outer roots.

Step 5
Because bonsai plants live in such shallow pots, it’s best to secure them in position with fine tie-wire. To do this, run a length of wire beneath pot and feed it up through drainage holes, as shown. Cover drainage holes with 2 small squares of plastic mesh, to prevent soil loss.

Step 6
Cover base of pot with potting mix. Sit plant in the pot and secure wire around root ball.

Step 7
Fill remainder of pot with potting mix, pressing it down firmly around the edges.

Step 8
Spread a layer of fine gravel over the top of the soil as a mulch.

This freshly pruned buxus will regrow after a couple of years into a densely foliaged tree, like the specimen on the right.