How To Prune Boxwood

How-To's, Landscape Care · Written by Roger

120 Comments

Boxwood happens to be one of the most common plants around, especially if you consider all the varieties there are.  I certainly don’t mean common in a negative sense.  Boxwood and all its varieties often serve as the backbone to many beautiful (and functional) gardens.

To Shear or Not To ShearSheared boxwood before

With Boxwood most people instinctively shear the plant.  The vision most of us have is one of perfectly shaped forms.  It definitely is at the top of the list when it comes to formal gardens and topiary.

I’d like to suggest two circumstances when “selective” pruning might be the alternative to shearing.

  1. when boxwood is used in “natural, informal gardens”.
  2. when boxwood starts to decline because of too dense branching at the outer ends of the main stems.

Boxwood used in natural, informal gardens.

It’s such a reliable, solid performer; I often use boxwood in natural settings.  In these gardens the boxwood are pruned selectively by hand to encourage the plant to stay full and strong while keeping a soft, mounded shape.

Dense, outer growth causes decline.

Overtime a constantly sheared (and formal) boxwood can start to decline in health.  This could be because of a number of conditions, e.g. poor internal air circulation that could promote disease or insect infestation.  The fact is plants naturally are not conditioned to have all their foliage concentrated just on the outer portion of the branches.

To improve or maintain the health of a sheared plant, you can selectively prune out a portion of the dense, outer growth.  If done right this will allow more light and air into the interior without causing a dramatic change in the look of the plant.

sheared boxwood afterTopiary Boxwood

I’d like to focus on shearing because this is by far the most common way people prune boxwood.

These first 2 pictures show the before and after of a Boxwood ‘Wintergem’ that was sheared.

This is a recently planted boxwood that was sized at 24 – 30″.   At this young stage you have the perfect opportunity to set the proper shape for the future of this plant.  Although you can often correct misshaped plants, it’s not easy and usually takes 2 to 3 seasons of growth to see improvement.

The fundamental rule in shaping a plant is wider at the base and taper towards the top.  There are 2 main reasons for this:

  1. It’s healthier for the plant because light is better distributed to the foliage.
  2. Aesthetically it’s more attractive and logical that the plant be wider at the base.  You want the plant to appear as though it’s connected and well-anchored to the ground.

In the sketch below I give a couple of typical shapes you would shear plants both the “right” and “wrong” way.

sheared plants right and wrongIt is not easy to develop these proper shapes with wider bases.  Plants naturally grow a little weaker and thinner towards the bottom.  Also, it’s been my experience that most people want to cut an equal amount off the plant all over.  That doesn’t work!

If you look at the first picture of the unsheared boxwood, notice how the greater amount of growth is concentrated towards the top.  The bottom and lower sides naturally have less growth.  Now look at the plant sheared in the 2nd picture.  The lower portion of the plant was not touched by the shears.

handshearsI still happen to use a pair of hand shears for trimming topiary plants.

You should develop a system or pattern to how you shear a plant, get good at it, and then repeat that pattern from plant to plant.

I shear plants in a clock-wise direction.  I imagine the proper line the shrub should have and follow it.  Regardless of how much or how little foliage there is, stay on that imaginary line. If you need a little help and guidance, for the straight lines take a length of wood like a 1 X 2″ (or anything like that).  If you just hold it up once in a while to show the line you’re trying to create, it can really help guide you.

gas hedge trimmerYou more often see power hedge trimmers today for shearing topiary plants.  They are powerful and quick.  If kept sharp and in skilled hands they can do some nice work very productively. In unskilled hands…I’d rather not talk about it.

When to shear plants.

Generally it’s best to let the new growth finish and “harden off” a bit before shearing.  From a practical sense the plant should not grow much (if at all) after that and the shape should stay nice until the following growth season.

If you happen to trim early, occasionally I have seen new, soft growth scorch a bit if the weather got hot right after the shearing.

On some properties plants might be sheared twice because the owner does not want to wait for the growth stage to completely finish.  So it’s done perhaps midway during growth and then again when it’s finally finished.

These are the main considerations when pruning boxwood and many of these points apply to other plants as well.  However, it’s so important you consider each plant and their “specific” preferences and requirements.  Like so many things, the skill starts with the right knowledge.

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    120 Responses to “How To Prune Boxwood”

    1. Peggy Says:

      It has to be that old, as the old farmhouse started out as a half house in 1767, then raised to a full two story.
      What is the best way to send a photo?

      thanks,
      Peggy

    2. Roger Says:

      Peggy,
      The best way to send a photo is in an email to me. Here’s my email address: roger@landscapeadvisor.com

      Perhaps I shouldn’t presume you know how to do that. Please let me know.

    3. Rose Says:

      Hi, Roger!
      Which do you prefer best, green mountain boxwood or winter gem boxwood?
      I noticed that the winter gems foliage are darker and shinier than the green mountains,
      and can boxwoods stand partially shaded areas?
      Thanks!

    4. Roger Says:

      Rose,
      Green Mountain Boxwood and Wintergem Boxwood are different in growth habit too.

      Green Mountain will have a slightly more upright habit, while Wintergem will grow more mounded (height and width similar).

      Both will take partial shade, but experience has shown me that the more light the better.

    5. cindy Says:

      Hi Roger,
      Ive just purchased two winter gem boxwoods from Menards and the tag on these plants said they get 2 ft tall by 2 ft wide. I wanted to be sure and so googled and now I have no clue because each website says something different.If they do indeed get bigger than what the tag says, is there a way to keep them at that size? These are going to be close to my walkway and so I cant have them big. Ive already regrettably had to pull out two different shrubs that were there and it about broke my heart. Poor little babies grew so well for me…and oh boy did they grow ! Couldnt prune those types.

    6. Roger Says:

      Cindy,
      I know what you’re saying about varying information, particularly with plants that are one of many cultivars under a genus. The botanical name for this plant should read: Buxus microphylla ‘Winter Gem’.

      There’s so much opportunity to have variations, mis-labeling or incorrect labeling. It’s just not an exact thing, especially when you’re trying to fit a plant to such a “limited” space.

      In my experience, ‘Winter Gem’ gets larger. I’d say 4’x4′ is more realistic.

      Have you considered Dwarf Boxwood (Buxus sempervirens ‘Suffruticosa’)?

    7. Cindy Says:

      Roger,
      Wow. Thanks for the quick reply. It’s so rare these days.
      Yes, I did consider dwarf boxwood. That was my intention when I was looking for an evergreen for that spot. The tag does call it by its proper name, but says 2×2, so I thought it was somewhat of a dwarf. I dont know weather to take them back or plant them and prune heavily to keep them the proper size. I have a little bit more room to play with than 2 ft, but definitely dont want anything over 3 ft. Maybe Ill just bonzai the heck out of them and hope they survive the drastic cuts ? Decisions decisions. Wish I understood more about pruning.

    8. Sonja Says:

      Hello All,

      I just got a wonderful new position to work in. I’m responsible for a wedding venue and super excite. It includes a little pond and lots and lots of plants of course.

      The formal part is the boxwood. So here my question, I have 26 boxwood bushes and I’d like to shape them into balls. Is there such a thing as a form for that so that they will all look alike?

      Thanks for your help!

    9. Roger Says:

      Sonja,
      Congrats on the new job. It’s so great you’re taking the time and interest to research the right way to do things.

      First off, what shape are the boxwood currently in? If they have been shaped differently over a period of time, you’ll need to proceed carefully (if at all).

      Realize that beneath the foliage will be stems and branches which form the “interior” framework for the current shape. If you trim/cut too aggressively into that interior branching it could look terrible and possibly not recover too well or too quickly.

      If you’d like to email me a picture of the boxwood, perhaps I could give you more definite advice on how (or if) to proceed.

    10. Bonnie Says:

      Hi,
      All my boxwood have been done from cuttings from one plant over the years.
      This April and May were so dry and the fact that my garden was on tour in June meant I did not do my usual cut back….I knew this winter was tough and that there would be die-back under when I cut them.

      I use a power cutter, as I have many boxwood. I then go back and cut out some “lace” holes with a hand clipper, I was told this is good for the plant.

      It is now July….so do I just leave all and cut early NEXT spring? Or can I cut them now? Thanks, Bonnie

    11. Roger Says:

      Bonnie,
      We’ll do a lot of our shrub pruning through the summer, including boxwood.

      I’d suggest you do a light trimming with the power shears and then “selectively” thin out some of the branching for the plant-health benefits of more light and air circulation. You mentioned “lace” holes — I imagine you’re referring to the thinning-out cuts I just mentioned. This is such a good practice you’ve been following.

      Here’s an article I wrote about Pruning Big Boxwood that talks a bit about this trimming/pruning strategy.

    12. Carleen Says:

      I’ve noticed a strong odor where our winter gem boxwoods are planted. It smells like cat urine. Other Internet sources have stated that the odor could be from our boxwoods. These are right under our living/dining room windows. Before I start throwing down cayenne pepper or moth balls to deter the few neighborhood cats, do these particular boxwoods throw off that type of smell? Thanks.

    13. Roger Says:

      Carleen,
      Normally, the bad smell of boxwood is associated with Common Boxwood (Buxus sempervirens). Winter Gem is a cultivar of Buxus microphylla koreana. And I personally have not experienced the smell with Winter Gem.

      I guess it’s time to get the moth balls and cayenne pepper out. :-)

    14. Carleen Says:

      Thanks Roger for the quick reply. I guess it’s off to Walmart! I’m glad it wasn’t the boxwood since this is the 3rd year that they are in and they are gorgeous.

    15. Laura Bilger Says:

      I have 4 year old little leaf boxwood that I have only lightly pruned and never shaped. Now they are big enough, I would like to shape them. When would be the best time to start shaping the boxwood?

    16. Roger Says:

      Laura,
      Now is the time we do our “general” trimming work, i.e. mid to late summer. And boxwood would be included.

      If I’m doing a more severe cut-back to renovate the boxwood, I’ll do that in the spring.

    17. Rose Says:

      Hi, Roger!

      I have dwarf boxwoods and winter gem boxwood, what is the best fertilizers for boxwoods and how often
      should I apply it
      Thanks!

    18. Roger Says:

      Hi Rose,
      I would use a general, organic fertilizer for the boxwood like Espoma’s Plant-tone.

      Once a year would be fine, and early spring would be a good time.

    19. Kathryn Says:

      I would like to plant boxwood in planters about 5ft long, 3 feet wide and 2 ft high. The first question is whether they could thrive in a planter of that depth. The second is whether there is a variety that would grow about 2 or 3 ft high (or could be trimmed to that height) and that could be kept to a depth that would allow me to plant annuals in front. I would like to create a year-round visual barrier, but also have seasonal color. Do you have a recommendation for a suitable variety of boxwood? I have yet to order the planters, so I can adjust the size if needed. Thank you very much.

    20. Roger Says:

      Kathryn,
      We plant boxwood in planters quite often. After all the years of observing how they perform, I look at it (and advise my clients) that its really temporary. Eventually the evergreen succumbs to the years of being confined to the planter. After all, like all woody plants its natural life is “in the ground”. But you will get plenty of years of enjoyment and function from the boxwood in the planter.

      In terms of the particular boxwood variety to choose, I’m going to suggest you download the “Boxwood Guide” on SaundersBrothers.com. This boxwood nursery put together this guide with many of the varieties used today. It’s so informative and helpful I ordered the hardcopy version, which I refer to all the time. This guide will give you all the information (mature size, form, etc.) that you’ll need to pick those that will work for you. Also, after picking those that might work, the next thing is availability. You’ll have to call around to nurseries in your area, but at least you’ll have the accurate names of the varieties.

      Hope this helps.

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