How To Prune Upright Junipers

How-To's · Written by Roger

52 Comments

There are a number of varieties of upright juniper. Some of the more common ones are: Torialosa, Robusta, Blue Point, Moonglow, Pathfinder, Skyrocket and Wichita Blue.

This category of juniper fills a useful design niche in the landscape. Most stay relatively narrow, yet grow tall. Sometimes referred to as columnar or fastigiate.

Typically they are very hardy, drought tolerant, and adaptable to a variety of conditions.

Often, however, upright juniper are not pruned, but allowed to “go-it on their own”.  This usually causes an open, lanky growth habit.  As a result they have a less than stellar reputation.

Once you understand the characteristics of upright junipers and how to care for them, they’ll become a useful plant in your landscapes.

A Common Characteristic Not Talked About But One You Need To Know

Qualities that make most upright junipers useful in landscape design are:

  • their narrow form
  • their hardiness
  • their unique texture

There’s another characteristic that’s common to most, and that’s how they grow.  All their growth energy goes to the terminal ends of the main branches. If not “selectively pruned” regularly these branches keep getting longer and heavier.  This causes each branch to stay thin with minimal side growth and eventually pull away from the center of the plant.

upright juniper prunedLost Cause?… Not Necessarily

In the picture above is an upright juniper we planted a few years back.  This was a tough spot to select a plant. The space was narrow, but height was needed.  The exposure was full sun so the heat got intense in the summer.

This upright juniper (sorry, I don’t remember the exact variety) fit the bill.

But look what happened.  The maintenance company  either overlooked the pruning, or didn’t know how.

So is this plant now a lost cause? Not at this point. You can still save the plant and reverse its decline by:

  • “Selectively” pruning back the terminal end of each branch to reduce its length and weight.
  • Using Arbor Tie to support the sagging branches by guying them to the center stem of the plant.

upright juniper branch tiedPruning the terminal end of each branch removes the apical bud and encourages lateral or side buds to grow.  This naturally makes the plant grow fuller and stronger.

The Arbor Tie lets you pull the branch back to its correct position and hold it there.  These ties should be temporary until the branches get stronger and hold their position on their own.  This might take 2 or 3 years.

Even though the Arbor Tie is temporary you must make sure there is room for growth and movement.  This PDF on Arbor Tie shows some uses and applications, but you can improvise too.  This is great stuff and I keep a roll in my truck for all kinds of situations.

The picture below shows the upright juniper after being pruned and “arbor-tied”.  Notice how selective pruning maintains the natural character of the plant.

If you use a calendar program like in Microsoft Outlook, or some other scheduling system, set a date to check the arbor ties (e.g. once/year). Don’t forget about them.  They must be monitored and eventually removed.

upright juniper pruned properlyThe Benefits of Rescuing Plants Poorly Maintained

You have to use your judgement here because sometimes it just doesn’t pay to put in the time and effort. In this particular case the task took me 20 minutes; with a good outcome – well worth it. Once again you have to compare the cost of repair (and the expected results) with replacing the plant.

Also, we all like to see a plant saved if possible and there can be real value there for the ecologically-minded homeowner.  Many customers will really appreciate the effort and professionalism.

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    52 Responses to “How To Prune Upright Junipers”

    1. Andrea Says:

      I have a Blue Arrow Juniper, about 5 feet, planted almost one year ago in Seattle. It was well watered until winter, and is now watered regularly in summer. We had an unusually dry sprung, however, when it was watered only irregularly. A couple months ago, I noticed the two leads at the top were brown (about 3-4 inches). The rest of the tree seems healthy and now the new growth seems uniform over the tree. No sign of pests. Should I simply cut out the brown leaders? (In general I get worried any time the leaders on a tree or plant look compromised.)
      Thanks for your help.

    2. Roger Says:

      Andrea,
      Hard to say why the tops died back like that. Let’s assume it’s because the plant was new and not established, and simply more vulnerable to stress (e.g. heat, drought, transplant shock, etc.). And die-back like that can manifest itself well after “the event/circumstance” that caused it.

      Evidently it’s stabilized so that it’s pushing new growth uniformly (except for the top). So yes, I would prune out the dead leads down to live growth. The plant should eventually assume new, dominant lead growth.

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