Repotting Situations, With Notes

This week, an assortment of puzzlers from this spring’s repots, with comments. 

A Japanese Beech with an unfortunate root system. Chunks of roots have died, identified by being black, unlike the living ones, which are light brown. Spraying with water helps see which is which. Then cut away the black areas until you see healthy tissue. 

Here is a Japanese White Pine with a similar issue. One possible reason for a pocket of root death is that the tree dried out completely, causing root death in areas, then was watered as usual, and then rot sets in. Correction is the same as with the Beech. It is easy to get air pockets when removing big chunks of the root mass like this, so have large mounds of new soil wherever there is a hole under the root mass before settling the tree in, and take more time chopsticking in soil. Having a “porthole” through the nebari helps drop soil in.

This one is an aesthetic decision—removing a high, ugly root on a Japanese Black Pine.

Cutting off the root.

Root removed, leaving one with some shari on it just below, which slopes into the soil better.

Approach grafting roots on a Rocky Mountain Juniper. This technique is not used much to get better juniper nebari, but rather to shorten an uninteresting trunk to the area it starts to get jazzy. U-pins with protective rubber hold 1/4” roots into grooves cut in the live vein.

A sharp, stainless steel spatula used in a stab-it-kill-it repetitive chopping motion is handy for removing the bottom snarl of roots on trees like this Japanese Maple. 

An over-large and over-long surface root on a Japanese Maple is shortened. Red circle indicates a side root of some size that will take over.

After whittling back with a ball cutter, the wound is smoothed with a chisel. Good idea to sterilize and seal wounds on Japanese Maple due to some of the diseases that can enter wounds on this species.

A Red Maple that came out of a narrow, rectangular pot. The nebari of this tree has been squoozed on the front and back and needed more room. White cloth is to keep the trunk clean while grabbing. 

On the left, the pot the Maple came out of. On the right, the one it might go into.  

In this pot there is more room for the front and back roots. Another reason to choose a pot is for better root spread.