Tree volcano request
This is a new experience: after years of reading and writing about the tree volcano epidemic, I actually had a client’s friend request that I install one. That’s like showing drugs to police officers. So, of course I said no but I’m not sure if the man understood me because he only spoke Cantonese.
Now, if you read my blogs regularly-as you should- you’ll know that I will do anything for a blog post idea. Which is why I took the job of maintaining a Chinese-owned “ghost” house. You’ve read about these houses if you live in British Columbia’s Lower Mainland. It’s a nice house but it sits empty and the neighbors whisper about it.
My job is to cut the grass and weed the place. And the weeding isn’t easy because the place hasn’t been weeded regularly (weeds produce copious amounts of seeds) and the mulch is so depleted, you can see the landscape fabric underneath.
This fig tree had a volcano around its trunk: note the wet bark and adventitious roots developing from the trunk. Two huge problems with long-term consequences.
Tree volcanos
This is one of those hard to explain garden habits that refuses to go away. After planting a tree, people create a volcano mound with soil or mulch maybe because it looks pretty. But it kills trees. This is how. (Disclosure: I learned everything about tree volcanos from my mentor Dr. Linda Chalker-Scott.)
a) Any soil or mulch piled up against the trunk will moisten the bark and invite disease in. You can clearly see this darker area in the photo. Yes, it takes time but it will be trouble for the tree.
b) Inside the volcano, the tree pushes out adventitious roots from the trunk. That’s not where roots should come from. As these roots mature and circle inside the volcano, they will girdle (strangle) the tree.
Now, I tried to act this out for the Cantonese man because my Chinese language skills are limited to very bad words about your mother. I pointed to the adventitious roots and then I put my hands around my neck to simulate choking. I wouldn’t be surprised if the tree had a volcano around it on my next visit.
No more volcanos
When you plant trees, make sure the root flare is flush with the ground. Yes, you can install a little bit of new soil but never against the trunk. Dr. Linda Chalker-Scott says it should like a donut. The soil never touches the trunk, stays mounded in the middle and tapers towards the edge of your tree well. If you have a tree well. In this instance, we planted the fig tree in a bed.
Mulch volcanos will rot the bark and invite diseases in; and they also give rise to adventitious roots that, over time, strangle the tree as they grow and circle inside the volcano.
Now you know. Call me if you need help.
