How To Prune Upright Junipers

How-To's · Written by Roger

17 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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    17 Responses to “How To Prune Upright Junipers”

    1. Ruth Uhl Says:

      I have blue point junipers planted next to my house in the flower bed. I have been told that the roots are invasive and may grow into the foundation of my house, also into the line to my septic tank. Should I remove the blue point junipers?

    2. Martha Says:

      I must have pruned my blue point juniper’s last yr. and got the pruning tip from a blue star juniper I believe it was quiet hot when i pruned them thinking this does not seem right. They filled back out and looked beautiful. Now i see they should have been pruned in spring. now that it is mid may is it too late to prune them.
      One had to be sprayed because it should signs of brown dying spots. Now better and so pretty.

    3. Roger Says:

      Hi Ruth,
      I would not classify Blue Point Juniper as having a particularly aggressive root system (compared to some plants that are notorious for that).

      The plant(s) should be at least 4-5′ away from the foundation and not next to or on top of the septic line. One thing to think about is where the septic’s leach field is. There, the juniper’s root system will want to grow into that space and possibly compromise the septic field’s function.

    4. Roger Says:

      Hi Martha,
      Frankly, I would not be too concerned about when you prune the juniper. These plant’s are so tough they should handle it no problem.

      I know I’ve pruned upright junipers in the summer heat and not had problems.

    5. Yolanda Says:

      Roger,
      Thank you! I have been lookingforinatructions on repairing the branches on our skyrocket junipers that are leaning out of shape after recent heavy rains. Your instructions on pruning and juniper ties will be put into use today. Thanks!

    6. Eric Says:

      Hi Roger:

      Lots of great tips on your site.
      I have 2 Sky Rocket Junipers that were planted in what is now too confining a space.
      I have been told to shear them back, but I see no such recommendation anywhere else, so I’m hesitant to go so. What I really need t to reduce girth and a bit of height.
      How can I reduce girth w/o giving them a too narrow bottom compared to the middle?
      Is limited shearing indicated to shape them?

    7. Roger Says:

      If you need to reduce the girth mostly, I would first prune the heaviest (thickest) shoots and branches back selectively with hand pruners. You want those heavier branches to be shortened back into the body of the plant; beyond where you ultimately want the foliage to end.
      I’m not a fan of shearing junipers like this. Shearing just cuts all the ends of the branches, which causes dense lateral growth at the point. The result is a “rat’s nest” of heavy branchlets at the outline/exterior of the plant, and little to no growth on the interior. Not good.

    8. Katie Says:

      Hi Rodger, Thanks for all your helpful information. I am planning on buying 6 Moonglow Junipers (6′-7′) to use a living fence (privacy). After doing some research I found that it can mature up to 6′-8′ wide. I am looking to keep the tree as narrow as I can. Can you recommend how I should trim in order to achieve a more narrow tall Juniper? Also what would you recommend as far as spacing between each tree?

    9. Roger Says:

      Hi Katie,
      I don’t have direct experience w/ Moonglow, but I suspect (from what I’ve read) that it has similar characteristics to some of the other upright junipers.

      Ideally you don’t want to use the plant where you’ll have to do an excessive amount of pruning to keep in in-check. But it sounds like you’re doing your homework to avoid this.

      I would discourage shearing as a trimming method. Shearing promotes dense growth on the exterior of the plant and that’s not good for several reasons, but primarily because it limits light and air from getting into the body of the plant. Rather, use selective pruning to cut back the main stems and branches, and even “thin” the plant(s) out a bit occasionally.

      If you space the plants approximately 6′ center-to-center they will eventually touch, but I think that’s what you’re after.

    10. Mike Says:

      Roger,

      I have two skyrocket junipers in my front flower garden, one on each side of the window. They’ve been there for a couple years and I’ve noticed that one is growing faster than the other, thus it’s about a foot taller right now. Is there anyway to trim the height of it to make it stay even with the other plant? Thanks,

    11. Roger Says:

      Mike,
      You might have to do the pruning over a couple of seasons to get the two plants equal. Right now, if you haven’t already, prune the taller/larger plant fairly aggressively and prune the smaller one just slightly, e.g. just the tips.

      Eventually you should be able to get the two pretty similar in size and shape. Remember to use hand pruners and prune “selectively”.

    12. Mary Zupon Says:

      Roger,
      We have 19 Spartan Junipers that have severe winter burn. They are 10 years old and were just gorgeous. They have been fertilized with Hollycare and watered frequently since April. These plants have received fertilizer every year and adequate water even buckets of water last winter when it was so warm and dry. We are in zone 5-6. Eleven of the plants are very brown with very little green underneath while the rest are partially green. Do you have any suggestions of what to do next?

      Thank you, Mary

    13. jen Hamilton Says:

      We have two blue point juniper trees that were starting to look like Christmas trees (really heavy at the bottom, touching the ground). We made the mistake of always shearing. We wanted the columnar look. Which was going to be difficult to achieve considering how wide our trees were at the base. We had seem some pics online of trees thay had the lower branches cut back to the trunk. So we cut off some of the lower branches. Worked great with one. The other looks awful (didn’t even have a “main trunk” just a big rats nest of branches?). I hope I didn’t kill them, and I hope they will look better next year!

    14. Roger Says:

      Mary,
      I’m also in zone 6. This past winter was rough on so many plants. Here it is July and we’re still pruning out die-back from winter damage. Almost every property has something damaged (or dead).

      It’s hard to determine if and how each plant will recover. As you’d expect, the more a plant is showing green, the more likely it is to eventually recover.

      It sounds like you take exceptional pride and care with your plants – and you’re doing everything you can to help them along. I don’t know how practical it is (considering the number of damaged plants you have), but when you’re clear on what’s dead and what’s living on each plant you could selectively prune back to just the green (living) points on stems and branches. It can help the plant recover, and it just helps make it look more presentable in the meantime.

    15. Roger Says:

      Jen,
      I’d have to see the Blue Points you pruned (at the bottom) to give an opinion.

      That technique of removing lower branches and exposing the trunk/stem can work really well. And you can take the time to select the branches you might cut, and even grab & hold them down to help you visualize how it would look – but it’s still an “adventurous” move.

      I don’t believe you killed them…or even hurt them. And maybe over time; with new growth, they’ll become the plants you’re hoping for. :-)

    16. iva Says:

      can Blue Point Juniper grow and live inside with no direct sun, only daylight (office w/ 2 smaller windows). Thanks.

    17. Roger Says:

      Iva,
      I don’t have any experience growing woody plants indoors. And I can’t say I’ve ever seen a juniper variety growing indoors.

      As far as I know, juniper is typically grown outdoors, and at that prefers full sun. So I don’t think it will work for your situation.

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