One of my trees seems to have skipped fall – and winter – and is now acting like it’s spring.
New leaves emerging on a Japanese plum (Prunus salicina)
Over summer, this tree suffered from a fungus that attacked the foliage (see “Diagnosing spots on Japanese plum” for details). After treating for the fungus, the tree lost all but a handful of leaves. This was right about the time when the temperatures climbed to 100 degrees F. As a result, the tree began to bloom and send out new shoots.
Plum blossoms in fall
What can I do about this?
If I’m worried that a deciduous tree is about to leaf out in fall, I’ll place it under a bench in the coolest and shadiest corner of the garden. The less light and heat the tree experiences, the less likely it is to continue growing.
If the tree continues to leaf out, it may not be much of a problem. Last fall my young plums grew strongly into December and kept their new leaves through winter and into spring.
The wrinkle is when a tree that leafs out in fall needs repotting. Sometimes new growth appears right as the old leaves begin to fall off which leaves an impossibly short window for repotting. In these situations, I’ll make case-by-case decisions.
If a tree has started to leaf out and there’s no turning back, I’ll repot right away, but I won’t be as aggressive with the roots as I would if the tree were dormant.
If the tree has mostly leafed out, I’ll either postpone the work or do a much less invasive repotting.
I’m hoping that the weather cools before this plum grows much more so I can repot as planned in December. If it continues to leaf out and it can’t wait another year for repotting, I’ll go ahead and repot with care.
Update about bonsai winter care
Your feedback was above and beyond what I expected – thanks so much to all of you who contributed! I’ll share a post on the topic soon. In the meantime, I hope your winter preparations are going (or have gone) smoothly!
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What to do if your trees think it’s spring?
Pretty simple: convince them it’s autumn.
My chojubai has started to flower again…I’ll be removing the flower buds 🙂
Bart Bieliński says
Great article Jonas! The subjects You’re presenting are so close to what I am experiencing, that I am starting to think You live in central Europe, just next to my place 🙂
Jonas Dupuich says
Ha, thanks Bart! It’s comforting to hear that these are common situations. Do let us know if you have some good central European topics to cover and I’ll see what I can do to help!
David Campbell says
My plum has gone through the exact same scenario this fall. Lost leaves to fungus early, bloomed a little and leafed out again. Now it has a nice set of new leaves and looks very healthy. If we ever get a fall and winter here in NorCal maybe it will shed its leaves. I will watch it closely for repotting. Thanks for the tips Jonas!
Carol Novak says
Could you slow it down with a refrigerator? Some people use that for winter dormancy.
Jonas Dupuich says
I think that would work well. I’ve seen people use refrigerators to good effect and think it’s a good option for keeping trees dormant.
The other option would be to drive the tree to a colder location at a higher elevation. I sometimes winter trees at a friend’s garden to make sure they go fully dormant.