Deciduous trees lose their leaves for part of the year. You can see fantastic shows of yellow, orange, and red in autumn when this does happen (depending on the tree species). Some deciduous trees lose their leaves in preparation for winter (such as in temperate or polar climates). Some deciduous trees lose their leaves during a dry season depending on the amount of rainfall. These types of deciduous trees are often found in tropical, or subtropical regions. Deciduous trees are suited to surviving colder weather conditions because of their ability to shed leaves. Although this also means that the leaves need to be grown back each year, which can require a lot of the tree's energy. There are also semi-deciduous trees which lose their leaves as new leaves begin to emerge. Semi-deciduous trees are known to keep their leaves year-round but shed them at certain times of the year due to cold or hot conditions. Every tree species is different though.
Deciduous is a popular bonsai choice for a number of reasons. Beginners will often choose a deciduous bonsai because of the incredible show of colours in autumn. You may also hear that a lot of deciduous bonsai are harder to kill than other species. This is mostly true. In early spring, you can cut a Chinese elm down to almost a stump and it will grow back well. (Don't do this unless you're working on a very healthy tree that hasn't had this done recently). Another reason that deciduous bonsai is a popular choice for bonsai is that they have a rather attractive winter appearance to them. The fine leafless branches make the tree look old and beautiful. This visual appearance also allows you to assess your bonsai's branch structure more easily as there are no leaves in the way during the winter months.
A deciduous bonsai will require more water than most other types of bonsai. This means keeping on top of your water regime, especially during the peak of summer. Overall, there isn't much to dislike about deciduous bonsai as they are generally beginner-friendly beautiful trees.
An evergreen tree keeps its leaves year-round. A lot of trees fall into this category. The majority of conifers (cone-bearing trees) such as the juniper and pine are evergreen trees. You also have broadleaf trees such as the sequoia, and eucalyptus which are evergreen. Evergreen trees lose their leaves gradually and not all at once like a deciduous tree. The majority of warm climate trees are evergreen. In colder parts of the world, you will find fewer plants that are evergreen, and those that you do find will be conifers, as not many broadleaf trees cannot withstand the severe cold.
I mentioned the term broadleaf above. A broadleaf tree species is a part of a diverse group of trees that have flat leaves. Most deciduous trees are broadleaf (apart from the larch tree and others), and you could say that the opposite of a broadleaf tree is a conifer, because a conifer has needles instead of broad leaves. More on conifers later though!
Depending on the type of evergreen bonsai you choose, you will have to adjust your watering habits and care. A broadleaf evergreen bonsai will require frequent watering and a slightly shaded spot in summer. A conifer evergreen bonsai will require less watering and full sun position in summer. I'm speaking very generally here, always refer to the species care guide for your tree.
Now you have a basic understanding of the evergreen tree. An evergreen tree doesn't lose its leaves all at once like a deciduous bonsai. The evergreen tree will gradually replace its leaves over the year. An evergreen tree might be a broadleaf or conifer. A broadleaf tree has broad leaves and a conifer has needles.
A conifer is a cone-bearing tree that is part of a small but ancient division of plant species. Some examples of conifers include the juniper, kauri, larch, pine, spruce, and redwood. Most conifers grow well in extremes such as hot or cold climates. This means that conifers are best grown outdoors! When it comes to conifer bonsai, you should be prepared for the long game. Some of the oldest trees in the world are the bristlecone pines in California which are estimated to be over 5,000 years old. Deciduous and broadleaf evergreen trees may have fast growth going for them, but conifers are the living saying of "slow and steady wins the race!"
The conifer has the most classic bonsai appearance to it than most other types of bonsai tree. When someone says bonsai, you think of an old magnificent twisted tree with green-needled foliage pads. Perhaps the bark of the tree is cracked and has fissures running down the trunk because of old age. Nothing says 'ancient tree' quite like an old conifer.
When it comes to growing conifer bonsai, some species are harder to grow than others. Pines, for instance, are among the most difficult species of bonsai to develop because the growth pattern of their needles is hard to direct. Different bonsai require different techniques to maintain their shape. For instance, most conifers require pinching techniques to develop refined 'pads' of growth. It takes patience to a grow conifer bonsai and skill to develop the bonsai even further. Growing a healthy conifer bonsai is something that will give you a lot of satisfaction and contentment for years to come. A beginner should not be deterred from owning a conifer due to its complexity. Learning & understanding is the most satisfying part of practising bonsai!