Harry HarringtonArtist and Author, Bonsai4me · Author, Publisher, Webmaster, Bonsai Artist

Repotting a huge yamadori Hawthorn bonsai in Autumn

22 Sept 2025 · 2 min

Watch on YouTube

1:38

In this short instructional reel, Harry Harrington documents the autumn repotting of a large yamadori Hawthorn bonsai that he collected in 2019, just before turning 50. The tree, one of the biggest hawthorns he has ever collected, is repotted with the assistance of apprentice Toby Wilson. The video explains why autumn is the optimal season for repotting deciduous bonsai: it allows the tree to develop new roots over the next six weeks before leaf drop, ensuring vigorous growth in early spring rather than spending the first months of the new year establishing roots. The process involved removing all retained original soil, fitting the tree into a new one‑meter‑wide pot, and using a custom soil mix of pumice, chopped bark, and a small amount of akadama. The timing aligns with low leaf transpiration, as daytime temperatures average 15 °C and night temperatures fall into single digits. After repotting, the hawthorn is left outdoors on display, to be styled once the leaves have fallen.

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So this is a big hawthorn that I collected 6 years ago in 2019, just before I turned 50, and it's fair to say it's one of the biggest hawthorns that I've collected. This short reel just shows the process of repotting the tree yesterday with the help of apprentice Toby Wilson. Now this is autumn repotting, And the purpose of it is the tree can grow plenty of new roots in the next 6 weeks before the leaves drop, and next year it shouldn't miss a beat. I should get full growth from early spring instead of the tree spending the first months of next year growing new roots. It was important to remove all of the old ground soil that I'd retained to ensure that the tree recovered from collection. And after a very tight squeeze into its new meter-wide pot, we used a mixture of pumice, chopped bark, with a tiny bit of akadama. This is a very safe time of year to, to repot deciduous trees, as the transpiration from the leaves is minimal. Our day temperatures are now down to an average of 15 degrees and single figures at night. The hawthorn will now be left out in the garden on display, ready for me to style when the leaves drop.