Acer palmatum katsura dropping leaves in June

Question

I recently bought a potted acer tree (Acer palmatum katsura) from a garden centre. However, it is now dropping leaves (14th June) and I dont know how to help it! The leaves drop very easily - if I move the tree slightly or brush up against it.

I live in England (North-West) so it is just coming into the summer months. It is kept on my balcony that is West facing and only recieves direct sunlight from about 4pm.

We did have a very hot May with lots of sunlight, and I think the leaves became a bit scorhed and perhaps I didn't water it enough. It has also been very windy, but I always try to move the plant to a more sheltered spot if the winds are excessive.

I have ordered some wood chippings to spread around the top of the pot to try and keep more moisture in.

I am unsure how to tell if it is pot bound? Although I have read you should repot before the growth season.

Any advice on how to help the plant and stop it dropping leaves would be amazing.

I attach some photos:

Answer 1

It doesn't look too unhealthy. The likelihood is you simply didn't water sufficiently well during the extended hot and dry spell we had in May, so ongoing, water when the surface of the soil feels just about dry to the touch, and water thoroughly, with a good couple of litres of water, allowing the excess to drain away freely (I am assuming the pot has drainage holes). Check the top of the soil daily, even if it's raining because very little rain gets into a pot. I do not recommend the addition of bark chips to the top of the soil, all they will do is stop you easily being able to check if it needs water or not;they are also unlikely to help because, if the plant is rootbound, the ratio of soil to root means it cannot hang onto water to keep the plant supplied for a few days, rather than it evaporating from the surface. You will likely find it loses more leaves, unfortunately; plants do this as a stress response (drought or other environmental issues) in order to keep themselves alive. Windy conditions will cause white marks and frazzling of the leaves - sun from 4pm onwards shouldn't be a problem.

It likely does need a larger pot, but it will be easier to repot when the leaves have fallen in autumn, so look to find a suitable pot in the meantime; ensure the new pot is just as deep, if not a little deeper, than the one it is in currently. You can use ordinary multi purpose potting soil, or that mixed with some John Innes No. 3 - the latter is the best for potted trees and shrubs, but it is loam based and much heavier than multi purpose, and on a balcony, it's best to mix them to reduce the weight, especially if you need to move the pot around. You can use ericaceous potting soil instead of multi purpose, but it's not essential.