Chinese Elm Care Guide
Chinese Elm (Ulmus Parvifolia) are one of the most popular and well known species used for bonsai. They can be grown both indoors or outdoors. It should be noted that if grown outdoors these trees will be more robust and grow much more vigorously as the growing conditions are more natural and consistent. You should know that there really isn't any such thing as an 'indoor bonsai' It’s just that some species will cope with indoor growing conditions. If grown outdoors these trees will need to spend all of autumn outside to acclimatise. If the tree hasn't been acclimatised properly and is placed outside midwinter it is likely to die.
If grown indoors place the tree in a bright window away from any drafts or artificial sources of heat like Tv's or radiators. If you have chosen a good location for your tree it will let you know by growing well and pushing out lots of new shoots. If your tree is growing well don’t be tempted to move it from place to place. Only move the tree if the current location is unsuitable or causing problems. Your tree can however be placed outside from late spring (after the last frosts have finished) through to the end of summer so it receives at least some natural light and air circulation. When growing indoors you are effectively tricking the tree into thinking it's living in a semi / tropical location causing the tree to hold onto more of its leaves during the cooler months. During the cooler months expect to lose some leaves and expect the tree to slow growth.
When a Chinese elm gets stressed it can respond by dropping its leaves. With some tlc the tree should bounce back and leaf out again within a few weeks providing you have found the cause of the stress.
If the tree is acclimatised properly and grown outdoors place it in full sun or partial shade. Remember the sunnier the location the tree is growing in the more water it will require. If the tree is acclimatised properly it will withstand light frosts. Whenever a heavy or prolonged frost is due it is a good idea to move the tree into an unheated shed, conservatory, outhouse or garage to protect from the worst of the weather. Once temperatures start to rise the tree can be placed outside again. If grown outdoors expect the tree to shed its leaves in the fall like any other deciduous tree. Once spring arrives the tree will leaf out again.
In our opinion when trees like this are grown outdoors all year round and are given a proper rest period (dormancy) through the winter they grow much more vigorously once spring comes around. They are also more robust and less susceptible to problems that can occur when grown indoors all year round.
Please note that all of our indoor Chinese Elms are actually grown outside all year round, so if you buy one from September to April expect these trees to have no leaves. From this point these trees should be kept outside at least until they naturally start to leaf out in spring. Once the have leafed out again they can be brought inside to enjoy if desired although as mentioned above we do recommend growing these trees outside all year round for the very best results.
When watering your bonsai tree, you need to be willing to adjust from day to day. NEVER water your bonsai tree to a schedule because the watering requirements will change on a daily basis depending on the growing conditions, ie growth rate, sunlight levels, wind, rain, temperature, time of year, etc…. Instead you should make a schedule for checking to see if your tree needs water or not. We recommend checking two or even three times a day during the warmest months, especially with an open and gritty soil mix that tends to dry out quicker than traditional soils. During the warmest months you might find yourself watering twice or even three times a day! In contrast during the cooler months you might only find yourself needing to water weekly or even less if grown outdoors. Don't allow these trees to fully dry out and in turn don't allow them to stay overly wet. Finding a good balance is very important. We recommend allowing the soil surface to dry a little between watering.
If you have access to clean rain water, we recommend using this to water your bonsai tree. If you don’t have access to clean rainwater then tap water is the next best option, although be aware if you live in a hard water area lime deposits can build up in the soil over a long period of time changing the Ph of the soil causing the need to treat with something to reverse the effects of the lime in the water.
When watering, remember that the soil we plant our trees in is very open, light and gritty. This means that it can easily be washed away if strong jets of water hit the soil surface. You should use a watering can with a fine rose for a gentle and even flow. You can water the tree from above or water the soil surface. If you choose the latter, you should at least water from above every now and then to clean the leaves of any dust or debris.
Feeding Your Bonsai
Replacing nutrients used by the tree and washed away when watering is very important. Generally, we feed through the growing season which can range from place to place and year to year. Once these trees start actively growing in early spring is the time to start to think about feeding. As the summer comes to an end and the trees start to wind down from the years growth is a good time to stop feeding. How you feed depends on what you want to achieve or what stage you are at with your bonsai tree. If you want to promote lots of growth and thickening of branches, then a heavier feeding program can be used. If you are refining a tree and want minimal growth a lighter feeding program can be used. Never feed a tree that isn’t actively growing and NEVER feed a poorly or sickly tree as this won’t make it get better and could even kill it.
For growing indoors we recommend using our Liquid Feed as instructed on the packaging.
For growing outdoors, we recommend using our Naruko Slow Release Bonsai Feed every 4 to 6 weeks.
Pruning & Shaping
If your bonsai tree is healthy and growing well, you’ll have lots of new shoots extending. Allow new shoots to extend from between 5 to 7 leaves and then prune back to between 1 and 3 leaves, pruning back to less leaves towards the top of the tree. Prune between the leaf node leaving a small stump that can be cut back later once its died back. Remember which ever direction the leaf you prune back to is pointing is the direction the new branch will grow in. Knowing this allows you to forward plan a branch structure for the future development of your bonsai tree. Another way to know when to prune a shoot is when it starts to lignify (make rigid and woody by the deposition of lignin in cell walls) The shoot will change colour starting from the base / origin of the shoot and work its way up towards the tip. If you want a shoot / branch to thicken then leave it unpruned and allow it to extend to thicken it. It can be cut back at a later date, once the shoot / branch is at the desired thickness.
Shoots growing straight upward or downward from other shoots or branches can be removed so the tree can focus its energy into more important areas. Doing this helps build a more natural looking branch structure. Each branch should have its own space to grow in. When branches are growing into each other wire can be used to place one of them into a better location. If this wouldn’t enhance the look of the tree, then the removal of one of the branches should be considered.
Heavy or structural pruning should be done during the winter months to aid in quicker healing.
Another method for shaping your bonsai tree as mentioned above is to wire the branches. If you have a branch in an awkward spot or need a branch to fill a gap, then wire can be used to place it into a more suitable location. The wire is then left on as long as possible without damaging the branch to fix the branch into its new place. Special wire cutters are then used to remove the wire without damaging the branches. This needs to be done before any scarring occurs. There are several methods that can be used when using wire to aid in the bending of branches. Guy wires are also useful for some bends.
Repotting your bonsai tree is a very important part of keeping bonsai over a long period of time. As your tree grows so do the roots. If you don't repot your bonsai it will eventually become pot bound and the health of the tree can slowly deteriorate, lose vigour and may even die. Root pruning and a fresh pot of quality bonsai soil will insure your bonsai tree stays in peak health. Chinese Elm should be repotted in spring as the buds begin to swell out. Your tree will need repotting every 1 to 3 years depending on vigour, size of tree & pot. Chinese elms prefer not to be pot bound so checking the density of the root system in early spring is recommended. If you find the roots growing around and around the pot, then it will be a good idea to repot your tree. Don’t repot your tree for the sake of it or out of habit because this can cause undue stress as the tree will need to recover. Keeping the soil surface free of dead leaves and debris will do the tree good and deter any potential pests and diseases. If any bug or fungal problems do occur spray or treat with a suitable product.
These trees are probably the best species for beginners to learn with. They are vigorous growers, very forgiving and easy to care for. If a mistake is made these trees usually bounce back. Don’t be afraid of giving the tree a good pruning as any pruning errors can be rectified in a relatively short amount of time. Mistakes have to be made for you to learn. They are perfect material for you to learn about pruning, maintenance and general bonsai tasks. We have insured all of our trees have had the very best start in life from the moment we receive them until the moment they arrive at your front door. We wish you all the best on your bonsai journey and hope you have many hours of enjoyment with your bonsai tree. We hope we’ve armed you with some basic knowledge to keep your bonsai tree happy and healthy for many years to come. Remember if cared for in the correct way these trees can outlive you the owner!