Pruning Mature Podocarpus

[taropatch]

Could use advice on pruning mature podocarpus (yew). The 25 footers will be topped to maybe 10-12 feet. How do you prune the side branches so they don't grow back so quickly? These side branches extend 5-6 feet. Cut all the way back to the trunk and let it make new side shoots or cut 'em back about half way? Thought some here may have already faced this dilemma and have some experience.

[kalakoa]

http://www.westhawaiitoday.com/news/loca...podocarpus

[taropatch]

good article on the tree. mahalo

[GoingFeral]

I took a stab at trimming my 32 trees myself but after 3 I'm hiring a pro with a lift. It would take me years to finish. It makes fantastic mulch if you run it through a chipper.

Can you feed podocarpus foliage to goats?

[kaialoha]

Aloha Taropatch,

Here's my spin on the subject based on me being a Landscape Architect (35 years) and former owner of a landscape construction, tree maintenance, and landscape maintenance company.

Your approach to trimming your trees is based ENTIRELY on what you are wanting to achieve in the long run. Not trying to be condescending in any way, but 'topping' a mature tree is actually the result of poor planning to begin with. Topping a tree is almost NEVER a good idea if it can be prevented.

1. What are you trying to achieve by topping the trees?
2. How old are the trees and what is the diameter, roughly, of their trunks 36" above the surrounding ground?
3. Are there a group or row of trees that have grown together too tightly?
4. Is it your intent to develop a hedge (BAD idea, at least related more so to that specific species) or to just reduce ('bring down') the size of the trees?
5. Are you trying to 'restructure' their appearance?

In general, trees should NOT be trimmed of more than 15-20% of their total mass at any one time, ABSOLUTE MAX. If there is some compelling need other than some immediate gratification of their altered appearance, you might want to think about thinning and lacing them over 2 to 3 cuttings spread 5-7 months apart, SLOWLY getting them to the shape you want them to be ultimately. When trees are topped, you severely compromise their health:

A. Sunlight that was blocked by the top of the tree before the topping is now able to penetrate through the canopy and sunburn the exposed trunk, branches, and new growth severely damaging the tree, possibly for years to come.
B. Improper pruning techniques can ruin the 'shape' of a tree and should be carefully planned before you make even the first cut (undercut branch first and then cut it from the top 2" FURTHER OUT than the first undercut and afterwards trim the remaining stub off completely. This method prevents stripping of the bark down the trunk, something that takes YEARS to heal from).
C. Removing too much of the tree compromises it's ability to produce enough food, transfer nutrients and support itself leading to the tree becoming weak and prone to disease which in Hawai'i, for Podocarpus, is a big deal.
D. Podocarpus are prone to Sooty Mold, and in Hawai'i the moist and humid conditions promote it even worse than other places. AND, Sooty Mold is one very good reason Podocarpus (or for that matter, ANY plant/shrub/tree) should NOT be 'hedge-cut'. While we want our privacy, 'hedging' shrubs and trees is a GUARANTEE and invitation for any number of plant diseases. If you want 'privacy', well placed plantings can act as a screen as they grow in over time.

If you want advice on how to prune/trim/thin and lace these trees, feel free to ask me any questions you might have ~ ~ ~

MUCH Aloha ~ ~ ~

Kaihekili