[music playing]
Good morning! I'm Jody Gale, Extension agent with
Utah State University Extension Service. This morning we're going to demonstrate
how to prune a thornless honey locust. We're located here at the end of March in
Sevier Valley. This is a good time of year to begin
pruning many ornamental trees, you don't want to prune ornamental trees and shrubs
in the fall, that's best done in the spring when the saps are just barely
starting to flow within the tree. The disadvantage of doing pruning in the
fall is you create wounds where you have a lot of desiccation and tissue damage
associated with moisture loss from pruning wounds.
So we recommend pruning primarily in the spring when the sap is starting to flow
within the tree.
I'd like to demonstrate tree structure for a few minutes.
This particular thornless honey locust has a very prominent central leader.
A central leader is essentially the trunk of the tree.
You can notice that the trunk goes up standing quite high up into the top of the
tree here. It's good to let a tree develop a center
leader and then have the branches go out from that center leader.
It enables the tree to have that very vigorous upright growth, that's how they
want to grow, that's kind of how the genetics are, so instead of fighting
against the genetics, it's good to prune them and train them with that center
leader. Not all trees are successful in developing
a center leader, sometimes they die at some point and we need to make
modifications when that would happen.
I'd like to show weak angles versus strong angles.
This particular branch, this is a fairly narrow view right here and is a fairly
weak angle. This one, however, is quite wide.
The limb is going out on much more of a slope, it's not as vertical, this angle
allows the tree to grow over time and does not develop a prominent bark inclusion
right here. This tree limb then is much stronger than
this one. Another good example is a little further
up in the tree here, this is a very strong angle, you'll notice how wide this is,
that's what you want to try and develop and look for in pruning both ornamental
trees as well as fruit trees. Thornless honey locusts are very common
to have very narrow angles, that's kind of how the genetics are, but with a little
bit of careful pruning, and if you really want to get into it you can actually
develop a spreader that you can wedge in between the center leader here and the
limb out here consisting of a small piece of wood with a sharp nail on either end,
the nail beam embedded in the bark, and just carefully pull the limb out when the
tree is very young and the limb is flexible and wedge that spread in there
and leave it for a couple of years and that will help to open up those angles and
make them quite a bit stronger.
What we'd like to show now is the importance of pruning to a lateral branch.
You very literally get an opportunity to choose the direction the tree would grow.
And that is done carefully by selecting buds or selecting limbs that are on the
underneath side of the branch going in an outward direction.
You want to avoid limbs that are growing into the tree such as this one.
These are the types that you want to automatically remove that are growing into
the tree, the idea is to direct the growth out.
So this is very vertical, very upright. It's often referred to as water sprout
growth. That's the type of wood to remove and
out here on the end you can choose these buds that are on the underneath side and
the outside such as this one right here going fairly far out on the new growth
from the previous year and that will develop the limb going this way.
If this bud right here were to be selected that would force the growth to go up which
is a disadvantage, you want the wood to go out.
This wood from this point here to here, this is the growth that occurred last
year. And so you want to do a little bit of
pruning to carefully control how that would go, I'm going to select this bud
here, bringing this limb this direction, this one that direction, and over here
we'll select this bud to carry this direction out that way.
This is the southwest side of the tree. Here in Sevier Valley we often get a lot
of wind this way, so it's important to bring the limb out as far as we can
through pruning and training to withstand that type of high winds.
Okay once you've decided and understand fully the concept of the center leader,
pruning these limbs as we've described a few minutes ago to lateral branches, it's
a matter of just going through and kind of cleaning up some of the branches inside
the tree. This particular pruning tool is very
handy, it has a ribbon that slides within the cable.
Here in the top it has a little mechanism that squeezes the jaws together and it's
also adjustable to extend or shorten it to fit the needs of the tree.
And it makes it quite handy to just simply pull on the handle to make the pruning
cuts. So we'll begin and start and do the
trimming. You'll notice that from right here clear
out to that top end that all grew the previous year that's much too long growth.
That needs to be shortened back, not too short, but I'm going to be careful and
select the proper bud, pruning those off, and shortening them back to a point where
they need to be. This branch is kind of moving sideways
into this branch so it's a candidate to remove entirely.
So we'll take that one out.
This one is growing vertical into the tree, we'll take that one out,
This is a hanger coming down, we'll trim that one off.
Don't want to take them all off. These branches are growing out from the
side and by making this cut here this is referred to as a heading cut, it will
force branches to come out in this area on the branch this coming season.
These are kind of hanging down so they're candidates to remove, this is a good one
coming out to the side, but we're just going to tip it.
We'll make a heading cut.
These very tall ones we'll select a bud
choosing the direction we want that limb to grow, perhaps that one there.
You have two here out on the end of the limb, this is inside very vertical.
This is more going out the direction we want it to go.
So we'll choose to take this one off and we'll make a heading cut to force this
to continue its outward direction. This is going sideways back into the tree,
we'll remove that. These others are good limbs going the
direction we would like, we'll just simply make a heading cut back and allowing them
to go. You've notice I've left a little bit of a
stub here it's a good idea to try and clean those fairly close, if they're left
too long they don't heal over very well. Well this is pretty well done, this is
pretty well done there's a small amount of work that needs to be done on these lower
limbs. If you're like me, when you're running the
lawn mower, you don't like to have it knocking your hat off.
So these are good ones to prune off that are quite low towards the ground.
Okay, we're starting to get quite a bit of work done, you'll notice there's a number
of limbs on the ground here. Pruning ornamentals you don't need to do
lots and lots of wood removal. It's good to be kind of in the 10 to 15
percent range. The primary objective is mostly to be
training and develop the tree structure without removing too much wood.
The more wood you remove, the more vigorous the tree will grow the following
year with promoting lots of good growth. As described earlier in this segment -
video segment - the new growth is quite long in this tree because it was pruned
very heavily a year ago in order to correct some serious structural problems
that's demonstrated by the before and after photographs - still images.
And so we want to be careful and not prune too much, but if we fail to make the
adequate cuts, structural defects will persist and later on - 10, 15, 20 years
down the road with wind storms and snow storms, with weak angles you can often
lose very significant structural limbs within the tree.
When the trees are young is the time to make the corrective, needed decisions and
cuts to be able to promote good structure on the trees.
And there you have it. Pruning a center leader thornless honey
locust to develop stronger angles and stronger branches.
Thank you for joining us.