They pinch the shrubs so we must prop the arbs

Some problems have no solution. All we can do is to share the pain and ease it a bit with laughter. For instance, whyizzit that:

...we're so wowed by plant bushiness?

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Growers say they absolutely must pinch shrubs to make them chubby, or they will not sell. It's a classic example of the hidden consequences of impatience because this answer serves a short term need -- making the sale -- while ruining the plants' long term chance for beauty.

Arborvitae as poster child

Arborvitaes are the case in point. An ice storm put a load on this arborvitae's trunks (right) and they splayed outward. The ice is gone now and the sap's risen but the trunks have not come back up. We'll fix that by propping the bent limbs.

Prop, don't tie


It may seem logical to tie branches like this together for mutual support but don't do that if you can prop, instead.

Any cord strong enough to hold these limbs together is probably not going to disintegrate in a year. Yet in a year the branches gain appreciably in girth and can be girdled by the ties -- cut off as if pruned. Even if the cord or wire is looped on just one side of the trunk, the amount of pressure it exerts can kill that side of that limb.

Threading the tie through tubing does not help, except perhaps to prevent chafing. The pressure is just as intense and is still exerted along a narrow line through the tube.

If tying is necessary, think of it as belting. Use material that can distribute the pressure such as the straps used to make seat belts or tow lines. In a pinch we used nylon stockings spread wide. Even then, make the belting temporary or consult an arborist to have the tree cabled.

Right: This arb is propped with a forked branch we saved while pruning other trees. The prop is marked with blue to help you see it.


  First make some props.

  It's spring so we're doing a lot
  of pruning, including removal
  of junk trees along a property
  line. So we don't have to build
  props from lumber, as is some-
  times done. We have large
  branches with sturdy forks to
  choose from.

  Left: We've trimmed this
  buckthorn branch to end in a
  natural crutch.

How long a prop should be is hard to guess, at first. We start with props as tall as the splayed plant would be if it was upright. If you enlarged the image at the top of this page you saw this particular prop -- an arrow points to where it's leaning against the wall.

Below, right: We push the prop branch's base into the ground, lean its top into the center of the arb, and position the arb trunk in the crutch.PropArbCN9502s.jpg

Sometimes we can arrange the prop so the bent branch stays put on its own. Sometimes we tie it in place. We tie loosely; we don't want to immobilize the limb since swaying wood builds strength. We use hemp that will rot away in a year or less.

These props only have to remain in position until new cells growing in the arb trunk become woody. A prop is temporary but we usually view it as a year-long fixture. It's simple to check if it's still supporting weight. Sometimes we remove one after six months, another may be necessary for 18 months or two years.


Below: So here's that arb with one side propped.







  Now before we prop any more limbs we're going to prune to leave the shrub
  with just one leader.

   Pruning: What makes a balanced arborvitae

We aren't willing to prop these plants every time winter weighs heavy. So we're also going to prune to keep this from happening again.

Pruning might not come first to mind as a solution but it not only answers in this case, it does so with a full-circle rightness. Pruning by the grower to make the plant look bushy is one of the main reasons the tree can't right itself now, and pruning can correct that.

Arborvitaes are trees; one trunk can serve for a lifetime. They happen to tolerate pruning (can remain healthy even when repeatedly cut back) so they make fine hedges. However, right now forget the hedge. Imagine an arb growing as a tree with just one trunk. In that situation with even light on all sides, the plant's weight is evenly distributed. Every face has about the same amount of wood and foliage. If something bends the trunk, it has a good chance of regaining its old orientation once the weight is gone.

However, that balance changes if the tree develops multiple trunks -- perhaps when its original trunk is injured, browsed or pruned. Each trunk has an interior, shaded side and a side that receives more light. More foliage and branches grow on one side. Each trunk is more likely to be overbalanced by a snow load and is more likely to remain bent to the side with most foliage even after the snow is gone.


Cuts that un-do past pinches


We know growers pinch arbs and we've faced the consequences, so when we buy we look for least-pinched arbs. (Which means starting smaller, usually!) We also un-do the results of the pinch as soon as we can. That is what we're doing now, pruning to give one trunk dominance over the others, so it can take off, regain natural balance and give the tree the chance to right itself after bad winters.

 We assess the competing trunks and select one that still has green, leafy twigs along the face that was shaded by other trunks. Those are essential, even if very tiny. Without those, the trunk will not be able to develop new branches along that side.

Right: We haven't propped the other splayed trunks because we'll be cutting them short and they probably won't need support, then. We aim to leave the trunk we've already propped in a situation where it is tallest so it will become dominant and the tree will have a single, balanced trunk from here on up.

Below, left: We cut out one of a pair of competing trunks on the propped side of this arb...

PropArbFN9506s.jpg PropArbGN9512s.jpg

Above, right: ...and we cut all the other trunks shorter. All that we cut is laying on the ground. Sometimes we can remove just one competitor to make a new leader but what you see here is more often the case.

Done and quickly recovered


Now the arb is propped upright and pruned to one leader. No more propping is necessary.

Here's a second arb before and after the same prop-and prune routine.

If the arbs' symmetry seems off, keep in mind that's a temporary situation. The plants respond quickly in spring with growth from all parts in the light.

Below: Here are these two plants three months later, in August of the same year. The arrow points out a gap that's already filled with new foliage.






















Cindy Bakken

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