How to Grow Outdoor Bonsai Trees in Your Garden
Making a Space for Bonsai in Your Garden
One of the common misconceptions that people have about bonsai trees is that they are indoor plants. When new people come in to see us they tend to think that all of the trees we have can be grown indoors. There is frequently some disappointment when I show them the limited number of trees that can realistically survive indoors.
Most of the “interesting” trees are outdoor. Pine, Juniper and Maple are all outdoors. Most of the flowering trees including Azalea, Crab Apple, Cotoneaster, Mulberry, Wisteria and Pomegranate* are all grown outdoors. All of the native British trees are outdoor.
So the way to grow these trees is to make space in your garden for bonsai trees. The good news is that it is easy to create the right environment in gardens large and small. Let’s have a think about how to grow outdoor bonsai trees in your garden.
Bonsai Are Not As Fragile As You Might Think
New customers often think that bonsai are fragile and hard to keep. They’ve often had a couple in the past and struggled to keep them alive indoors. As this hasn’t worked out, they now believe that they are hard to keep. It is much harder to keep trees alive in a home setting than outdoors. Your house is usually hot, the air dry and there isn’t much light. Trees generally like cool, humid air and plenty of light. The limited number of trees which are grown as indoor bonsai tend to come from tropical parts of the world, making them able to cope with the kinds of temperature we find comfortable in our homes. Many of these trees such as Ficus naturally grow in forest settings where light levels can be low, meaning that they can cope with the lack of light indoors. Other species such as Portulacaria come from arid dry landscapes and so can cope with the lack of humidity in our homes. Other trees are selected as indoor bonsai due to their vigorous nature. In spite of selecting trees which have characteristics enabling them to be grown indoors, it is still more difficult than growing outdoor bonsai.
In your garden, bonsai need to be raised up so that you can see them. Good locations include on benches, tables and walls. Don’t keep them on the floor – you want to be able to see the trunks and all the nice structure of the branches. In our garden at home, we have sunk posts into the ground and attached a small plank to the top to make a T shaped stand. This means that we can control the height of the post, so that the tree is displayed exactly how we want. These posts can be placed into one of your flowerbeds, into the lawn or into a gravelled area.
A bonsai bench is another option. A basic bonsai bench can be nothing more than breeze blocks and a few lengths of 2×2 timber.
Some trees like to be grown in full sun, some in a semi-shaded spot. A good bonsai book with a species guide will tell you about this. I think a spot out of very strong wind is a good idea, so displaying trees against a fence would work well. You really don’t need a lot of space either. Frequently, neglected or unused parts of the garden will work well. I have seen great displays up against outhouse / shed walls, around the back of garages and along the sides of paths. Of course if you have a nice patio area or a pond, well-kept bonsai will make this an even more lovely space.
What about the cold weather? Let’s start by saying that not all trees are a sensitive to this as you think. Take the Chinese Elm that you’ve had in the past. These trees are hardy down to a least minus 5 degree, and probably even colder than that, possibly down to minus 10. Again, a good bonsai book (or bonsai seller) will be able to tell you which trees are hardy.
How to Provide Winter Protection
It is still a good idea to move trees into a protected location when the weather gets really cold. If you have a conservatory or greenhouse, then it is very easy to do this. If not, a coldframe, a wooden box with a glass lid is easy to build. If you have built a bonsai bench, the trees can be moved under the bench. Some other bonsai growers will protect the roots of their trees by wrapping the pots up in bubblewrap. Another way is to dig a small hole in your garden and place the roots of the tree into the soil, covering the roots up with soil.
Can’t I just bring them into the house? With some trees yes you can, though with most of the trees, this increase in temperature will make them sprout into leaf in the middle of winter, which will disrupt their natural cycle.
Deciduous trees do not need any light when they are not in leaf, so can be put into garages or sheds. Some people also say that evergreen trees can be moved into garages / sheds in winter.
One final note on this – don’t be tempted to move your trees too quickly. It is important for the health of your bonsai that they get the chance to go dormant over the winter. Being overly protective may mean that they linger on into the winter. Let them get a little cold weather.
We all know that sometimes it just never seems to stop raining for days. Don’t worry about the trees, they don’t mind this at all. I have never had a problem with too much rainfall, as the bonsai soil we use drains well.
Don’t assume that the rain will do your watering for you. It takes a period of sustained, fairly heavy rain to get enough water into the bonsai pot. A light shower will not be sufficient.
Other Plants Can Complement Your Bonsai
A wide variety of ornamental grasses are available in a range of colours. Some have attractive seed heads.
Bamboo look great with bonsai. Be careful about planting Bamboo directly into your garden. There are two kinds of Bamboo. Some are spreading and other are clump forming. Spreading Bamboo will take over your garden, and should be planted in planters. If you like, dig a hole in the garden and put a large plastic planter in the hole. This will stop them taking over. Clump forming Bamboo do not spread anywhere nearly as fast, and can be planted directly into the garden. A good garden centre will be able to tell you which is which.
Japanese Maples are available in a brilliant range of colours and leaf shapes. Get the best out of them by planting directly into the garden, in a position out of strong wind.
