Repotting- the basics

Hi all… can some explain why spring is the repotting time. Is there a video that explains this? is it species related. I can’t get my head around this. i loss too many trees repotting. If a tree has stored its resource in the roots for winter, we then disturb this as it wakes up?

Thanks in advance…


The best I can explain is this… In Spring with increasing daylight and progressively warmer temperatures the plant begins to move resources. The carbohydrates, water, nutrients and hormones present in roots and vascular tissue begins to accumulate in buds on trunk and branches. At this point the roots serve to anchor the plant and transport water and nutrients from soil or potting medium to the branch tips where the buds are located to fuel their growth. Roots also grow at this time as well, but primarily its going to be foliar growth.

So, when doing spring repotting I feel the key is to trim roots back, only removing overly coarse(thick) roots. The fine roots are the ones delivering nutrients and water to the rest of the plant. The thick roots have function as well, storage and stability to simplify thses are usually interior roots and nebari type roots.

So for me I do only as much is required to keep the plant strong and healthy. Disturb only what needs to be removed, use appropriate mix for the species.

I think most failures during potting/repotting is inconsiderate and over aggressive root work, far too frequent repotting and the number one killer is inappropriate aftercare. Aftercare including watering, sunlight and protection. Aftercare is plain complicated.

Tips for you watch Ryan’s repotting videos. Learn his method. Find nebari, reduce starting from greatest limitation (top, bottom, exterior), know what your removing, aeration and proper chopsticking.

Hope you find this helpful, good luck with bonsai.


Repotting time really is species related. On top of that, there are special care recommendations for species that have been repotted. Oh, and regions, too! Sheesh.

Example, you can repot azaleas in early Spring or in June/July after they flower. Then you don’t let it flower the next year.

Boxwoods can be repotted in early Spring, but I’ve had good luck repotting them on a cloudy day in August (Summer dormancy plays a part).

Bald cypress can be repotted just about any time, but I avoid doing it in Spring before the new growth lignifies.

Most frost-averse tropicals are best repotted when nights are consistently above 60°F.

As with all things bonsai, check with your local clubs first, then resources, then try to understand WHY it is the best time.


Thank u. For your replies.

I think i over worked before. One thing im finding from mirai. Dont over work the trees. .