Siberian Elm (Ulmus Pumila)
The Siberian elm is widely used as a bonsai when we are looking for medium to large sized trees, as its leaf is slightly larger than its cousin the Chinese elm. It is a deciduous tree that can reach 20 meters in height.
Siberian Elm Bonsai Care Guide
Like the Chinese elm, the Siberian elm is a relatively easy tree to care for that is ideal for beginners in the world of bonsai who want to try designing a tree of a certain size.
How should I water it?
It is a species that likes humidity, so we will give it abundant watering, but we will not spray it. We will not have to worry about the quality of the water; even with hard water, this tree can develop completely normally.
Should I leave it in full sun?
If we want to avoid cultivation problems, we should give it as much sun as possible and only put it in the shade in cases of extreme heat.
Should I worry about sheltering it during the winter?
It withstands sub-zero temperatures very well, yet we must not forget that the bonsai is in a pot, so the roots are more exposed than if planted in the ground. This means that in very large temperature drops, we must protect our bonsai.
How often should I fertilize?
As is usual with bonsai, we will only fertilize when the tree is growing. In this case, the Siberian elm is one of the first to wake up in spring and autumn; it is at that moment when we see that it is sprouting that we can fertilize.
When and how should it be pruned?
We recommend doing the main pruning along with the repotting at the end of winter or the beginning of spring, as this way we can adjust the number of leaves to the number of roots to prevent dehydration.
We can cut without fear, as it sprouts really well from the main trunk, so we can get new branches again if we need to. In fact, we must control the suckers that arise from the trunk so that the branches we want to strengthen do not lose steam.
Can I pinch the tree?
As it is a tree that grows so fast and does so almost constantly without stopping except in winter, we must control the silhouette of the tree, cutting the tips of the branches that we see are getting longer.
When and how should you wire?
A good time to wire will be in summer. We must check that the wire does not dig in, as the growth of this species is very fast and it can easily swallow the wire. If this happens, we will have options to make the wounds heal without many problems, as it has a facility for doing so.
When do I have to repot and how often?
We will repot before it begins to sprout, which would normally be at the end of winter. We cannot wait long between repots, as the roots grow very quickly and will soon run out of space. We can do drastic root pruning and complete substrate changes without this affecting the tree.
What substrate or soil should I use?
It is not a demanding species with the substrate either; even with compact substrates, the roots should develop correctly. But a well-draining substrate like akadama will be a good option to go a step further in the development of our bonsai. We can also mix 30% of kiryuzuna to provide some nourishment in the substrate itself.
How can I propagate it?
As it is a tree that roots extremely well from cuttings and air layering, this will be the fastest and safest option. We can also do it through its seeds, although it will be a longer process.
What pests and diseases can affect it?
The most common is the whitefly. We must especially check if the tree is new, as they usually arrive with whitefly larvae directly from the nursery. We can also suffer from green aphids, scale insects, and what will later cause sooty mold.
What pot should I choose?
We recommend glazed pots that match the color of the leaves, keeping in mind that we will not have a color change like that of maples. As for the shape, we must choose according to the style we want to give our bonsai.
Where can I buy an Ulmus Pumila bonsai?
It is a relatively easy species to find, as it is used in many towns in Spain as a shade tree in the streets.