There are some obvious signs that indicate when it’s time to repot a tree – like when the water fails to percolate or when a pot breaks.
Other signs are more subtle. When there’s a significant change in the amount of time it takes for a tree to dry out, for instance, it might be time to take a closer look.
This is often the case with my Yaupon holly. In recent weeks, the tree has been drying out within hours of the last watering.
Yesterday I found that the soil didn’t give at all when pressed firmly and digging down I saw that the akadama had broken down leaving nothing but brown dust and fine roots. I decided to repot.
Yaupon holly out of the pot
Had I checked underneath the pot to see if there were roots clogging the drainage holes, I would have seen none.
Although it’s often said that this is a good measure of whether or not a tree needs repotting, I’ve found it to be misleading as often as it is helpful. Here’s what the bottom of the holly’s rootball looked like after removing it from the pot.
Roots everywhere except for the drainage holes
It appears that the holly roots prefer moist areas to dry areas as roots refused to grow above the drainage holes. And it’s not as if the tree doesn’t have many fine roots. Here’s what the bottom of the rootball looked like after removing about 1/4″ of soil.
Lots of fine roots
I can’t say I’m surprised by what I found as I typically repot the tree every year. But just because I typically repot a tree every year doesn’t mean that I’ll automatically repot it. What it means is that I’ll check to see if it needs repotting every year and make a decision based on what I see.
Subscribe to Bonsai Tonight
New Posts Delivered Every Tuesday and Friday
Edward Stanton says
Jonas, another concise, informative, beautifully illustrated post. I would have inserted a sentence about trees that take TOO LONG to dry out–the opposite of your lovely Yaupon holly. As you know, reasons for this could be too much organic matter in the soil or even a poorly designed pot. All best to and BT!
Jonas Dupuich says
Hi, Ed – well said. Too wet is just as much a sign of trouble as too dry. Thanks for the note!
Bobby says
I agree Jonas, roots present in drainage holes are not a good indicator for a repot or not. Much of it comes down to reading your trees, knowing what their annual root growth is, how the specific species in your environment under your care behave, its stage in development, etc. Whenever I get a new tree I like to repot it at the first ideal opportunity, regardless of whether or not the tree or soil are showing signs of a required repot because that is such an important component to the future of the tree and a complete unknown until you get in there yourself.
Jonas Dupuich says
Thanks, Bobby! That’s exactly the approach I like to take – repot as soon as possible to see what’s going on.