|
The Complete Guide to Landscape Design, Renovation,
and Maintenance
by Cass Turnbull
RADICAL RENOVATION: TESTING THE OUTER LIMITS
What the guy down the block did to his rhododendron is criminal
mutilation. What I did to mine is radical renovation. That's how
I explained it to my wedding guest who stood aghast at a rhododendron
stump that had been cut back to four inches from the ground.
In another case of radical renovation, the subject was a 15-foot
x 16-foot x 8-foot sheared, ugly, never-blooming deciduous mock
orange (Philadelphus, sp.) hedge in a local park. I remember the
look on the caretaker's face when Lisa, a consulting gardener, and
I told him of our plans to cut it all back to the ground. These
types of radical renovative pruning are perfectly all right if you
know what you're doing. It is, however, a lot like surgery, and
hence recommended only in otherwise hopeless cases.
Cane-types, as I have mentioned before, can generally be started
over by cutting all the canes to the ground. It's often better to
do it in stages over years if you can. New growth on cane-growers
tends to be straighter and there are greater spaces between flower
buds. The more esthetically pleasing branches, the ones that arch,
are older. But, on the other hand, very old branches may begin to
show fewer flowers, on forsythias for example. So you need to weigh
the factors of height, number of flowers and arching habit when
deciding how much to prune. This is why removing one-third of the
canes for three years is a good idea, if you intend to renew your
shrub. In the case of the giant sheared hedge, it would have been
unrealistic to do it this way. You couldn't fight your way in with
loppers. So, if it is appropriate, get out the brush blade or chainsaw
and have at it. Be nice to your renewed shrub and give it lots of
love, old manure, and water to help it hit the comeback trail.
You can usually radically renovate most mound-type shrubs by cutting
out one-third of the growth each year, as with cane-growers, or
by cutting them totally to the ground as well. On stiffer branched
mounds, it is sometimes better to reduce everything to two or three
feet below the height at which you want them eventually to wind
up and to do a lot of thinning down inside as well. Escallonia is
a good example of such a plant. Once the plant regrows to the size
you like, you may "grab and snip" to keep it there.
 |
| To stimulate a bud to grow out and eventually become a branch,
nick the bark just above the bud with a razor blade. Make your
cut about the size and depth of a figernail clipping. |
Renovating--Restoring Tree-Likes, Non-Suckering Types
I redesigned my own yard as a novice gardener and made nearly all
the possible common errors. One of them was that I wanted full grown
plants to begin with, so I spent a lot of extra money on several
very big (four to five feet) rhododendrons instead of being cheap
and patient. These shrubs were thin and leggy because they were
grown too close together back at the nursery. Usually a leggy plant,
when put in the sun, will fill out naturally. I was impatient, and
I began working my own terrible experiments. As it turns out, even
many tree-like shrubs can be radically renovated.
You will have the best success in renovating rhododendrons in the
early spring. Some horticultural specialists say to start as early
as February, when it's getting warm and dormant buds are fat. These
are the tiny (pencil-tip size) buds, usually hidden on the branch
or trunk, ready to grow if natural disaster breaks out the top.
It's better to cut the tops back all at once on some broadleaf evergreen
shrubs like rhododendrons--not in thirds as you do with cane-growers.
If you cut back just one branch, the plant will choose to let this
branch die totally and meanwhile it puts its energy into the other
fork. But if all the branches are equally cut back, they must all
break bud.
 |
| The most common error when dramatically reducing plants is
not cutting back far enough. Leave enough room for your shrub
to grow back for several years, perhaps several feet. By then
it will have reestablished it's natural form. |
Be sure you are not working against a plant's natural habit. Your
type of rhododendron or other broadleaf evergreen plant has a size
and degree of openness that is characteristic of its species. A
large-leaved Loderi-type rhododendron wants to be twelve feet tall
and open. You cannot prune it into a hybrid-Jean-Marie-type five-foot
ball. It will simply grow back in an open form. Tree-likes that
lend themselves to renovation are naturally growing compactly with
small, closely spaced leaves. Inquire seriously, "Why is my
rhododendron leggy?" It may need water, not pruning.
What about my own rhododendron stump? The original plant was too
ugly for too long, and I have a deep need to test the outer limits
of pruning. So I had cut it to five inches from the ground. It's
coming back now in great shape.
 |
| After cutting back a tree-like, take care to help it regrow
a good new framework. Cut out too crowded, too spindly, and
wrong-way shoots. |
Most people can't bear to cut back the entire top of tree-likes
radically. Another option is to thin the top, so that light reaches
the interior, and then to score or nick the buds. Take a razor blade
and make a 1/8-inch-deep cut about 1/4 inch above one of the tiny
dormant buds as they plump up in the early spring. This will trick
the bud into thinking the top was broken out and it will begin to
grow. These buds exist clear down to the base of your rhododendron,
by the way. When you have enough growth below (in one to three years),
cut out the top. Nicking buds works on other types of shrubs and
trees, too.
Other kinds of tree-likes that can be successfully renovated by
severe pruning in addition to some TLC (Tender Loving Care) are
camellias, pieris, aucuba, laurel, photinia, Rose of Sharon (Hibiscus
sp.), laurustinus (Viburnum tinus) and evergreen euonymus. Don't
try it on the types that sucker back, particularly dogwood trees,
magnolia, or witch hazel (see helpful lists in the Appendix).
Things to remember: when you saw your non-suckering tree-like back,
it will look for all the world like plant mutilation. Be sure you
cut it way, way back, not just to where you want it to be. That's
because it's going to have to grow back for three years before it
looks like anything, and by then it will be three feet taller. After
cutting, train the new shoots and suckers to prevent the roller-coaster
effect we will soon discuss, and to build a nice framework.
 |
The strange regrowth of radically pruned
rhododendrons is due to the lower truss, which weighs down soft
new shoots. The shoot "hardens off" in that position.
Next spring, growth heads up again. |
One difference between a mutilated rhododendron and a renovated
one is how it looks six years later. The hardest plants to restore,
you will remember, are old, badly pruned rhododendrons. When you
step inside one of these, you see a roller-coaster ride of skinny
branches going every which way. Squiggles, zips, and wows! Retraining
regrowth is important in renovation. Cut or rub off the new suckers
or buds that are too crowded, or which face back through the center,
or are too, too straight up and ugly on any and all renovated plants.
Also, in the case of rhododendrons you find that the nice flower
blossom is the culprit in your roller-coaster. The nice green soft
new shoot that charges out from a chainsawed stump will get a big
fat whorl of leaves or a big flower head on it that will weight
it down.
When the branch hardens off in that position, you have the beginning
of your roller-coaster ride. I remove the flowers or cut back new
branches to a node or whorl of leaves in order to help keep this
from happening. After three years, you may let it bloom.
Some types of rhododendrons won't break bud; they'll just die. They
are the smooth-barked kinds. Most of the hardy hybrids won't give
up this easily, but if you do radical restorative pruning on tree-likes,
you must be prepared to have them die. They don't usually, but it's
very stressful for them. Be sure to water them and avoid high nitrogen
fertilizers which would encourage too much wild regrowth.
Caveats Galore
I almost omitted this section on radical renovation for tree-likes
because I have nightmares of what people will do with a little bit
of knowledge. I've already seen what they do with none at all. Radical
renovation is appropriate only when:
1. You have all the room you need for the plant to grow back to
its mature (not necessarily its ultimate) height.
2. It has been previously mal-pruned and is therefore too ugly to
be thinned out or opened up.
3. It is actually blocking a pathway or window and doesn't just
SEEM too big.
4. It has a naturally compact form, not open and tall.
5. It is of mature age (fifteen years old or older).
6. It is healthy and well watered.
7. It is not a suckering or finely-branched plant.
8. It is not a conifer or needled evergreen (except yews)
9. If the only other alternative is removal and you are prepared
that it may die from surgery.
10. If you know that it will take two to five years for it to look
good again.
11. If you do not use radical renovation to keep plants small, but
only to start them over.
SUMMARY
Radical renovation is a way to start plants over by cutting them
nearly to the ground. It works best with cane-growers and mounds.
It is possible but rarely appropriate with tree-like shrubs.
Forward to My Tree's Too Big
Back to Getting Rid of Unwanted
Plants
|
