Chinese Elm Care

Derwent the Chinese Elm, taken on arrival.

I purchased a Chinese Elm in late May this year. It arrived in a rectangular blue pot with soft, spongy soil, covered over with a layer of moss.

The tree was in leaf and looked perfectly healthy on arrival; in full leaf and showing no signs of distress. However, within a week of arrival, it began to show symptoms of root or soil-related problems.

The warning signs that gradually presented were:

• The water would not drain. It sat on top, ran off and came out of the bottom of the pot without showing signs of wetting the soil beneath the surface.

• Roots were visible, poking through the surface.

• Soil was mounding up around the base of the tree, lifting around the trunk. This is a classic sign of root binding.

I researched the issues I noticed and found that the tree was likely pot-bound. However, it was the wrong time of year to do major root work.

Instead of running the risk of causing the tree further harm, I poked holes in the surface of the soil to help with drainage and started to closely monitor the tree.

The plan was to let the tree grow through the summer and to then repot it in late winter/early spring. However, the tree continued to become distressed. It grew leggy twigs and branches, which is quite normal, but its leaves routinely yellowed and dropped, which is not.

Eventually, I took to YouTube, seeking out videos made by Chinese Elm bonsai enthusiasts. From them, I learnt that Chinese Elms are regularly imported in bulk and distributed with very little work having been done on them since their arrival to the UK. They are often potted in less than ideal soil, in pots that are too small for their root systems. Many suffer and die within months of purchase as a result, through no fault of the new owner.

What can you do, when it is the wrong season to give your bonsai tree a complete rescue?

Slip pot your tree, instead of giving it a complete repot with extensive root work out of season:

• Purchase a larger pot that will be 1-2cm wider all the way around.

• Use good quality substrate that will help to control the moisture retention in the poor-quality soil that your tree has to remain in.

• Avoid damaging the roots when removing the tree from its original pot. If the tree comes out easily without the use of a tool, that's ideal. If the tree is stuck, use a blunt tool to gently prise the roots away from the inside of the pot.

• Prepare your pot with mesh and wire, as you would in a normal repot.

• Add a layer of substrate to the bottom of the pot.

• Place your tree in the centre of the pot, ensuring that the gap is even all the way around.

• Add substrate all the way around your tree, ensuring that there are no gaps or air pockets.

• Wire your tree in place to ensure that it does not fall out of the pot or get knocked over.

• Wait a week before feeding your tree. I recommend an organic seaweed feed if your tree has been showing signs of stress.

• Wait a further week before pruning. This is probably an unnecessary precaution, but my tree has been showing signs of stress since late May/early June. I want to ensure that it has recovered well before I cause further stress.

If this is your first time, I recommend looking up repotting/slip potting videos on YouTube before trying to remove your tree from the pot.

The tree's old blue pot sits in the foreground. You can clearly see the original soil, sitting in the centre of the new pot. I think the unglazed, brown pot looks much better.