How to Trim Hedges

  • 01 of 10

    How to Trim Hedges Evenly Using Shears

    Picture of a pair of hedge shears.
    Using hedge shears for the job is more work, because you're cutting by hand, but hedgers are noisy. Whichever tool you use, you'll want to read this article to learn to come out with an even hedge. David Beaulieu

    The example I use in this tutorial showing how to trim hedges evenly with shears is a row of boxwood shrubs that I planted in my own yard. In fact, it is the same one to which I refer in my article on how to plant hedges.

    They say that there is more than one way to skin a cat. Now, mind you, I have never skinned a cat, myself (nor do I ever intend to, being a cat-lover!), so I will have to take "their" word for it. Be that as it may, I suspect that there is also more than one way to trim...MORE a hedge. What follows in this tutorial is, then, to be taken as a guideline, rather than as a set of instructions to be followed slavishly.

    After planting my boxwood hedge and fertilizing it, I pinched back new growth during that first year, to induce low branching. To do so, I did not set up a guide, using stakes and strings, as I did for the present tutorial on how to trim hedges; rather, I just "eyeballed" it.

    But now, in my boxwood hedge's second year, it is time to employ more precision in my trimming. I will be showing you how to get straight lines in your trimming in this tutorial. I should caution you, however, that the hedge-shape for which I am aiming in this second year is not the final shape my hedge will assume. Let me explain:

    After the second year of trimming, enough low branching will have been induced to set my hedge on the right track. But to keep these lower branches healthy, I will want to start trimming the top of the hedge to be narrower than the bottom -- otherwise, sufficient sunlight would not reach the bottom branches. You can think of the eventual desired shape as being that of an inverted vase.

    But for second-year trimming, straight sides will do. I did my trimming with manual hedge shears, pictured above. In Step 2 we will look at some of the other tools of the hedge-trimming trade....

    Continue to 2 of 10 below.
  • 02 of 10

    Supplies Used in Hedge Trimming

    Use stakes and string to get straight lines when trimming hedges.
    Use stakes and string to get straight lines for hedge trimming. David Beaulieu

    While electric hedge trimmers are useful for larger hedges, I preferred to use manual hedge shears to trim my small hedge. Whenever it is feasible to avoid machinery, I tend to do so, simply because it is so much more relaxing to work with one's hands and in quiet surroundings.

    Supplies Used in Hedge Trimming

    A carpenter's level and a string level are optional supplies for a hedge as small as mine, but they would come in very handy on projects involving larger hedges. The following are the...MORE supplies on which I relied for my hedge-trimming project:

    • String
    • Stakes
    • Mallet
    • Scissors
    • Pruning shears
    • Hedge shears
    • Tape measure

    Armed with our tools, let's begin the hedge trimming in earnest in Step 3....

    Continue to 3 of 10 below.
  • 03 of 10

    Setting Up Guides for Trimming Hedges: Pruning

    Information on pruning hedges.
    Prune off the "worst offenders" as you go, to make room for your string. David Beaulieu

    To trim a hedge and get it straight, you will want to set up stakes and strings, to guide you. Essentially, you "outline" the shape that you want the hedge to take; then you simply stay within the bounds you have set up, as you trim.

    But before we begin, I want to inject a sobering thought: it is not as easy as pounding the stakes into the ground, running the strings between the stakes, and then racing through the hedge with your hedge shears (as one might see in a cartoon).

    The problem...MORE is, the branches of the shrubs will keep getting in the way of your string, as you try to get a nice, taut line between two of your stakes. That is why I list "pruning shears" as a tool you need (see prior page), in addition to "hedge shears."

    Even though the hedge shears get all the glory, you will want to keep the pruners handy, too, throughout this operation. Using the pruners, you can remove the "worst offenders" -- that is, branches sticking way out -- as you begin to tie off the strings. After you have made several such strategic cuts, you will find that you are able to achieve the tautness in the string that you want.

    You will find that hedge trimming entails a little pruning, followed by a little trimming (shearing) -- you will have to play it by ear.

    In Step 4, we will get those first stakes in the ground....

    Continue to 4 of 10 below.
  • 04 of 10

    Setting Up Guides for Trimming Hedges: Lower String

    Picture showing how to use stakes and strings to get straight hedges when trimming.
    Stakes and lower string in place on one side of hedge. David Beaulieu


    1. Using the mallet, pound a stake into the ground at one end of the hedge, on one side of the hedge (in other words, at one of the corners).
    2. Repeat at the other end of the hedge (same side).
    3. Tie a string to one of these stakes, a few inches off the ground.
    4. Measure how high off the ground the string is, where you have tied it to the stake (so that you can match this height at the other end).
    5. Walk the string over to the stake at the other end and tie it off there, at the same height as for the first...MORE stake.

    The picture above shows what the result should look like (we will call this the "lower string").

    How deeply into the foliage of the shrubs should the string penetrate? Well, the idea is that any foliage outside the string will be trimmed off. In other words, what you are creating with the string is a line that will eventually become the edge of the hedge. It is up to you where that edge will be. But how severely you trim also depends on the type of shrubs with which you are dealing. Boxwood shrubs are meant to be shaped into hedges, so my trimming will be severe.

    There will be four strings, in all: a lower string and an upper string for each side. That number is somewhat arbitrary: I judged it to be sufficient for a hedge as small as my own.

    Initially, you should not tighten the strings too much, because you will have to adjust them as you proceed. For instance, as mentioned on the prior page, some of the shrubs' branches will be in the way, initially: you will have to prune them off, so that you can get in deeper with your string. Only after all such obstacles have been removed should you tighten your strings. Ultimately, you do want a nice, taut string.

    In Step 5 we turn to the upper string....

    Continue to 5 of 10 below.
  • 05 of 10

    Setting Up Guides for Trimming Hedges: Upper String

    Bottom and top string both fastened on one side of the hedge.
    Bottom and top string both fastened on one side of the hedge. David Beaulieu

    Repeat the directions on the prior page, except that this next string will be a few inches higher (we will call this the "upper string"), on the same side of the hedge. Measure up from the lower string (at each end) to the upper string, to make sure the strings are evenly separated from each other.

    Note that, to be really precise, you could attach a string level to each string, to ensure that they are level (assuming your hedge is resting on level ground). Also, using a carpenter's...MORE level, you could make sure that the two strings are plumb (that is, one directly underneath the other).

    In the picture above, notice that my upper string is not taut yet. That is because some branches are still in the string's way, and I have not pruned them off yet. I will prune them off and get the string taut before I begin shearing the hedge.

    In Step 6 we will turn to the other side of the hedge....

    Continue to 6 of 10 below.
  • 06 of 10

    How to Get a Straight Line in Shearing Small Hedges

    How to trim hedges.
    Stakes and strings all in place. David Beaulieu

    On the prior page, I began this discussion of setting up guides for trimming hedges, starting on one side. Now we move to the other side.

    Repeat Steps 3, 4, and 5 on the other side. The picture above shows all the guides in place: a lower string and an upper string, on each side of the hedge.

    Measure between the stakes at one end, to make sure that they are separated by the same distance; repeat for the other end.

    For a bigger hedge, I would use a carpenter's level to check, at this point, that...MORE the two upper strings are level with each other, all along their length. But for small hedges such as mine, this step is not necessary.

    With the guides in place, in Step 7 we begin the trimming....

    Continue to 7 of 10 below.
  • 07 of 10

    Shearing the Growth on Top of the Hedge

    Picture showing someone shearing hedges.
    Guided by the strings, trim off the top of the hedge. David Beaulieu

    I began by trimming the top, first. Use the two upper strings as a guide, and keep the hedge shears as level as you can. I found it easiest to trim on one side, first, then switch over to the other side and finish trimming the top growth from over there.

    In Step 8 we will move on to trimming the sides of the boxwood hedge....

    Continue to 8 of 10 below.
  • 08 of 10

    Shearing the Sides Evenly

    Information on how to prune hedges.
    This picture shows how much has to be trimmed off one side. David Beaulieu

    From the picture above, you can see how uneven the foliage is on this side of my hedge. Thus all the trouble that I am taking to shape my hedge, before it gets too old (the older a hedge gets, the harder it will be to shape it).

    All of this vegetation sticking out beyond my strings had to be removed. Keeping my shears as plumb as possible, and using my strings as guides, I proceeded to trim. When finished, I had a hedge with a straight edge. This is actually the easy part. It is getting the...MORE guides in place that takes the most work.

    About half way along the hedge, you can see that there was an especially large indentation. That is because one particular boxwood shrub in my hedge, for whatever reason, did not grow as fast in its first year as the others. It is because of this individual shrub that I had to remove as much vegetation as I removed in this project. Alas, as with people in a group, so it is with plants in a hedge: it seems that there is always one troublemaker.

    In Step 9 we will wrap up the trimming for this boxwood hedge project....

    Continue to 9 of 10 below.
  • 09 of 10

    Shearing the Ends of My Row of Boxwood Shrubs

    Picture of trimmed hedge.
    After photo: trimmed hedge. David Beaulieu

    After repeating my trimming on the other side of hedge, I am almost done shearing. I will finish by shearing off the excess vegetation at the two ends (near the stakes).

    I was not able to shear the "troublemaker" shrub much on one side (see prior page), because it set too far in, away from my string. So I went back and pruned it a bit, afterwards, instead. The light pruning will stimulate new growth and, hopefully, reform the troublemaker.

    Lastly, let me offer some advice about...MORE fertilizing in Step 10....

    Continue to 10 of 10 below.
  • 10 of 10

    Fertilize the Hedge

    Fertilize your hedge after pruning.
    Fertilize your hedge after pruning. David Beaulieu

    Fertilize the hedge to encourage further growth. I fertilized my hedge with compost. Between the fertilizing and the trimming, my hedge should be ready for trimming again soon. This is precisely what I want: as I continue my trimmings, the boxwood shrubs will fill in the hedge better and better.

    How often should you trim hedges? The answer will depend on the type of shrub that comprises your hedge, as well as on the degree to which you are seeking a "perfect" hedge. If perfection is...MORE not your thing at all, but you want a row of shrubs on your property for the sake of privacy, consider, instead, a "living wall" of shrubs allowed to grow into their natural shapes.