Crabapple Restoration Pruning

Posted by shane - January 4, 2011 - Pruning Techniques - No Comments
Crabapple is a very common and valuable landscape tree in Alberta.  It is one of the species I am most familiar with, having pruned it in almost every conceivable site from Calgary to Red Deer to Edmonton.  A neglected crab, such as the one below, offers a big challenge, even for the most experienced pruning professional.  The tree below is owned by Dennis Worobetz, in Red Deer, at 3322 – 44A Ave.  At first, Dennis wanted to remove this tree, and I’m sure most landscapers and pruners would have been happy to oblige.  I convinced him to save it and start the restoration process.

Neglected Yellow Crabapple before pruning

 
The truth is, on the Prairies, it would take several decades to achieve the height and girth of the Worobetz crabapple, so arborists should always consider crown restoration as opposed to removal.  Mature trees are too valuable a resource in the urban forest to hastily remove.
 
I approach a restoration job like this systematically, patiently working from one area to the next.  I started by using a 6′ orchard ladder and worked as high as I could under the crown and out toward the tips. I focussed on removing deadwood, diseased tissue (and their was a ton of it!), and finally set up  a new framework of branches that would begin to establish a strong and healthy structure for the tree, long-term.  I then repeated the process with a 10′ orchard ladder, reaching even higher.  Finally, I climbed throughout the tops and repeated the process for a third time.  The results were dramatic.

Crabapple after first restoration pruning cycle

 
I will prune this train again over the next 2 years, in late October, to correct the structure as necessary, and to train new growth in appropriate directions to fill voids within the canopy.  Thereafter, it may only be necessary to prune this tree every other year, in the dormant season, preferably in March or early April, before the buds swell.
 
 
 
 
 
 
 

Intended crown shape for this tree

 
The diagram to the left indicates the intended shape of the crown.  The arrows point in the directions that I’ll be encouraging new growth and/or training new
branches.  Eventually, over several pruning cycles, I’ll achieve a balanced, elliptical shape for this tree.  It certainly isn’t necessary to create symmetry in ornamental pruning, but in this case, that’s what I’m after.
 
Next year, I’ll revisit this tree and discuss the extent of new growth, and explain what I will have done on the second pruning cycle.
 
 
For more information on pruning crab apples, or any other tree, please contact Shane at Wild Rose Garden & Tree Service at (403) 755-5899.