Willow Top: When is Extreme Pruning O.K.?
Monday, March 4, 2013 at 06:00PM
Howard Gaffin

Originally published in TCIA Magazine.


Flush cuts were still the norm when I began my arboricultural sojourn. In 1983, Dr. Shigo spoke at my alma mater. He was just beginning to obtain notoriety for challenging the practices of the past with modern science. A New Tree Biology would not be published until 1986. Tree response to wounding is being studied and documented. CODIT, and bark ridge pruning are introduced and tree topping is chastised.
So now I present to you a technique I will call “extreme heading back”, but really, I topped the tree, though not indiscriminately. I really wanted to call it entrenchment (a novel approach to managing veteran trees), but my methodology was far more primitive and abrupt.
I’ve performed extreme heading on my fair share of willow (and other) trees early in my career. It was commonly done, and at that point, I did what I was told. Slap on some spurs and climb on up. Make a cut at the desired height, slather on the tree paint, beauty! As I became more “educated”, the pendulum swung the other way. I was proud of my righteous stance on tree toppers, and they’re heinous crimes. I refused to do any topping what so ever. I knew stuff! Thirty years later, to quote Socrates, “The only true wisdom is in knowing you know nothing”.
While this technique will be rarely considered, there are times when the situation leaves little other options other than removal. The Willow (Salix species) I present here had considerable dieback in the crown and a lean toward the house. While the root anchorage still seemed solid, the hollow trunk was somewhat compromised.
Willow trees are poor compartmentalizers. They are subject to cankers, leaf spots, rust, tar spot, aphids, and leaf beetles to name just a few afflictions. The wood can be brittle and break apart in storms. Leaves, twigs and branches are constantly falling. The root system is aggressive and can ravage underground pipe. The….wait, why not just cut the $#%* thing down!?

Ok, the Pros:
- Likes wet conditions and is an excellent choice for areas with standing water, but can withstand drought to some extent.
- Not too fussy about soils, though does not like a high ph.
- Fast grower, usually strong regrowth response to loss of parts
- Aesthetics. Ah there’s the rub, maybe the deal maker. Imagine a hot, steaming, summer day in the shade by the pond. The willow crown bends to the will of a gentle breeze announced by ripples in the water....but I digress. The point is, they’re nice too look at.

Though the trunk of this tree was fairly compromised, it was also incredibly cool. Twisted and gnarled, it was hollow right through, but did exhibit good health and woundwood formation. If the risk could be removed, this tree might still provide benefits for years to come.
Once again, I whipped out the ANSI 300 pruning guidelines and specifications were derived. From the ANSI 300 Pruning Specification Writing Flowchart:
The Clients goal: Retain the tree, reduce the risk and create a structure to promote a low, spreading crown.
Considerations: Willow tree, fast grower, strong likelihood of epicormic sprouting.
Pruning Objectives: Reduce risk, remove stems exhibiting disease or decay back to healthy wood, encourage lower epicormic sprouting.
Pruning Method Options:
- Crown cleaning along with light reduction pruning.
- Crown cleaning with a combination of heading back and reduction pruning.
- Extreme heading back (client’s choice).
Specifications:
- Reduce stems to an approximate height of 15 feet.
- Actual site of cuts will be based on the size of the cut (the smaller, the better), evidence of existing decay and the presence of live growth or nodal areas.
- Remove any remaining dead, broken, or diseased parts.

A written proposal was provided to the client outlining the goals and objectives. We planned the work for mid-June. I felt the timing would be late enough to obtain some benefit from the current year’s growth, yet early enough to develop new shoots and promote some wound closure activity.
As access to the tree with an aerial lift was possible, and deemed the safest, most efficient way to do the job. We placed ¾ inch plywood on the turf, and maneuvered the aerial lift into position, maintaining a safe distance from the root zone. The pruning was performed to specifications, no one got hurt, and we didn’t break anything.
Upon completion, we stood back to marvel at our handiwork. Woof. Had we not been in a rural area I would have been moved to cover our signage and don paper bag head-gear. A younger version of me would have railed at this obvious catastrophe. Topping! Heretics!
OK, younger, smarter, more handsome version of me, ANSI 300 defines topping as: “Reduction of tree size using intermodal cuts without regard to tree health or structural integrity”. In this case, the cuts were made just above the nodes, with full regard to health, structure, and integrity. That’s’ right; extreme heading back.
We returned in September of that year to find a nice flush of growth emanating from all the remaining leaders, much to my relief. Another year later, the willow exhibits the type of crown envisioned. We will likely return soon to do some crown cleaning and thinning. The trees’ stewards are very happy with the results, and will likely enjoy this specimen for years to come.

 

Article originally appeared on Gaffin Tree, Certified Arborist, Consulting Arborist (http://www.gaffintree.com/).
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