Removing air-layers from an old juniper

What do you do with a San Jose juniper that has too many branches? Create some air-layers! At least, that’s what Kenji Miyata did.

I acquired a half-dozen junipers from Miyata last year, five of which came with layers in progress. Now that the weather has cooled down, I thought it could be a good time to see if there were enough roots to separate the layers.

In short, there were plenty of roots. Here’s what one of the trees looked like before getting started.

San Jose juniper with air-layers in progress

Curious to see what the individual layers looked like – let alone the tree itself – I removed the first branch. Here’s a shot of the roots.

Good surface roots

Even though roots aren’t as important in junipers as they are in other varieties, it’s still nice when you have some.

Miyata’s process for layering San Jose juniper is surprisingly simple. He ties an aluminum wire around the point below which he wants new roots to emerge, twists it tight, then builds a small pouch and fills it with fine bonsai soil. No cuts, no hormones – the roots just grow. Although I don’t know exactly when the layers were started, my guess is that it was earlier this year.

Here’s what the next branch looked like after separating it from the main tree.

One of the larger layers

A number of the layers will make cute trees.

Short layer removed

Tall layer removed

When I got to the last layer, I was dumbfounded as to how I’d remove it. I chipped away at roots until the top of a branch was exposed, but once it was cut, I realized that the roots had escaped their pouch and grew into the main root ball.

Branch cut, roots still connected

I figured my best bet would be to take the main tree out of the pot and carve out a wedge where the layer’s roots had grown. This was more work than I’d expected, but it appears to have worked.

The separated layer showing the roots that had grown into the main root ball.

Of course, the real test as to whether or not this “worked” is waiting to see how the separated layer grows.

A lot of foliage for a small amount of roots

Here’s what the main tree looked like after removing the last layer.

Layers removed

And here it is in its new pot.

After repotting

Altogether, this tree produced an impressive number of layers. Here are the five separated branches together.

Separated layers

I’ll be watering the foliage of the removed layers whenever it’s dry out, but I’ll be careful to not keep the soil too wet as the new roots get established. I often wait until spring to do this work, but I’m both curious how the layers will do when removed now and I’m trying to get a jump on repotting season as there are plenty of trees to repot in the garden this year.