Outdoor Bonsai grow differently to indoor bonsai, they will grow faster due to the natural light, natural seasons and rainfall. They may require more pruning and training during the growing season, to keep the desired shape.

Temperature:

Outdoor bonsai should be placed in a sheltered area, protected from strong winds, storms, hail and frost. It is best to raise the bonsai off the floor, to avoid damage from pets and animals.

Light

Place the bonsai in a sheltered area that has some shading during the day. You might ask, that trees can be in the full sun all day, why not a bonsai? Bonsai are potted in small pots with little to no space to store water and will quickly dry out in the baking hot sun.

Watering

A bonsai requires regular watering. The warmer the environment, the more often the watering, it could be once a day or once a week. The best way to gauge, is to touch the surface of the soil, if it is still moist, wait a day then test again. The hardier bonsais like the acacia trees are more resilient to dry soil and irregular watering schedules, but the general rule of thumb is not to let the soil dry out completely, and similarly not to overwater either, water logged soil can lead to root rot. 

The best time of day to water is in the evening, however during the warmer times of the year, you maybe required to water in the mornings as well, avoid getting the foliage wet if a hot day is forecast, as this could scorch the leaves.

During the winter months, reduce the watering to every two to three weeks

Humidity

During the dryer months, a bonsai can benefit from a regular misting, you can use a spray bottle and spray the tree foliage, two to three times a week.

Feeding

You should feed your bonsai every one to two weeks with a liquid fertiliser, starting in August, ending in April, allowing for dormancy in the winter months.

Yellow or falling leaves:

This could occur for a few reasons, such as a sudden shock, perhaps by a drop in temperature, or being very dry. Adjust the position of the bonsai to a more sheltered environment.

Some species, will naturally drop their leaves during its natural cycle, The tree is not dying and the leaves will be replaced four to six weeks later

Fungal Disease:

Bonsai are susceptible to fungal problems, just like trees in nature. Should you notice a mildew like mould growing on the foliage, use an appropriate fungicide.

White Threads on leaves:

This is most likely caused by mealybugs. Remove with a cotton bud dipped in methylated spirits then wipe the leaves clean, do this regularly until the infestation is under control.

Curling Leaves:

This normally indicates a insect, such as aphids or a spiders nest. Check inside the leaves, you can either remove by hand or find the relevant insecticide spray, to remove the infestation.

Water is not draining from the pot:

This is usually due to the growing medium degrading, which indicates that the bonsai needs repotting.

Roots are growing out of the drainage holes in the pot:

The bonsai will need to be repotted and the main root trimmed.

Brown tips on leaf edges:

This is likely due to scorching from the sun or the soil drying out. Move to a shady position and water more regularly.

Abnormally long, leggy growth:

This is due to lack of light, move the bonsai to a brighter location.

When:

Bonsai trees are best repotted in the spring every two years. 

What you will need:

You are going to need Bonsai repotting soil, pruning scissors, mesh and a suitable bonsai pot.

How:

Carefully ease the bonsai from the old container. Gently remove the soil from the root ball. Trim off about 30 % of the roots.

Cover the drainage holes of the new pot with mesh.

Add a layer of repotting soil to the bottom of the pot. Place the bonsai into the centre of the pot, hold it in place while you work soil in and around the roots, until the tree feels firm within the pot. Add and work the soil well until the pot is fill, being vey careful not to leave any air pockets.

Afterwards:

Water well from the top until there is run-off and keep in the newly repotted bonsai in the shade for three weeks to allow the roots to grow.

Start feeding the bonsai four weeks after repotting.