box lollipop tree - bottom is dead...

Hello, I have a pair of what I call Lollipop trees, - spherical box trees 5 feet high. The bottom quarter has died, its just twigs, and has been since last summer, but the new buds have come on the top parts.

I want to know if I should cut the twigs away and hope that new growth comes down and fills out the space, or cut off the twigs and let the top grow up so that I can regain the sphere shape higher up as it were....

Also why do you think it died off, they are in quite large pots, but a shady yard, they may have been left too long in a tray with water (now removed)
any advice helpful.

 

Hi olye,

Trees are fascinating organisms that are continually self-optimising in order to satisfy their conditions for growth, especially light and water. When a branch becomes no longer viable for the tree to retain it will shed it in order to regain some of the energy it's losing to it. For example; if a branch is no longer getting a lot of sunlight then it is not used for photosynthesis and therefore of no use to the tree. In this circumstance the tree will shed that limb and use it's resources elsewhere. From what you are describing I'd say this is what is happening to your trees - the lower half is no longer getting sufficient light to keep it alive. Instead the tree is putting it's energy into new regrowth at the top where it will get more light.

Keeping a tree's roots waterlogged is bad practice, but symptoms from this affect the entire tree and can show up a long while after.

Trim off the twigs as you see fit in order to achieve a pleasant shape and this should cause no ill effect to the tree.

Hope this helps,
Matthew

 

It could possibly also be box blight:

http://www.rhs.org.uk/Learning/Research/Projects/cylindrocladium.htm

Box is quite a hungry plant so it will be worth giving it a feed, cut off the dead as Matthew sudgests.