When to prune boxwoods

Trimming Boxwood Bushes – How And When To Prune Boxwoods

Introduced to America in 1652, boxwood shrubs have been gracing gardens since colonial times. Members of the genus Buxus include about thirty species and 160 cultivars, including Buxus sempervirens, the common American boxwood. The varieties are largely based on leaf size and growth which can range from one foot tall to twenty.

Boxwoods have fallen out of favor with some gardeners in recent years. They are the gardeners that remember trimming boxwood bushes into severe and often geometric shapes that have no place in the more casual gardens of today. They also remember how much time and effort it took to keep them in formal rigidity.

And that, my friends, is a shame.

Trimming Boxwood Bushes

Boxwood bushes have an undeserved reputation and should be a welcome addition to the modern landscape. When the right cultivar is chosen, they need very little pruning. Boxwood is easy to grow and thrives under many conditions that would defeat a less sturdy plant. Their compact evergreen leaves add texture and form to the garden when all else falls to winter’s sleep. Used as a hedge, nothing provides a better screen against an unsightly view.

That said, these handy evergreens do need occasional pruning. Boxwood, like most shrubs, needs a cleaning out of dead or twisted branches that can be harmful to the bush. Even when chosen for a particular size or shape, an errant branch or twig may need trimming. Boxwood bushes simply don’t need much care when compared to other landscape shrubs.

How and When to Prune Boxwoods

As with all shrubs, you should be asking when the best time to trim boxwoods might be and when should you prune. Boxwoods can be trimmed at any time of year, but, for plant health, it’s best to avoid shearing in the late fall. The new growth that appears after trimming boxwood bushes may not have time to harden off before frost.

Shearing or trimming may be done with hand shears or with electric hedge clippers. It is the removal of all or most of the most recent growth. Plant age should be taken into account when deciding when to prune boxwoods. Young plants actually benefit from frequent shearing. The best time to trim boxwoods to shape is during the first few years. This will encourage branching and new growth, which will result in denser growth and defined shape. But, don’t over do it.

Excessive shearing can produce growth so dense on the outside of your shrub that it will prevent light from reaching the center of the bush and leave the inner branches bare.

Removal of larger branches or pruning boxwoods is used to remove diseased or dying branches or to refurbish plants that are past their prime. Beware! Severely pruning boxwoods can kill the shrub. It’s best to take such drastic measures in stages, over several years if necessary, to give your boxwood shrubs the best opportunity to survive.

One last note: if you don’t mind a little extra work, boxwood shrubs make excellent topiaries. Topiaries are living garden statuary and can be molded into any shape your imagination can envision. They can range from one to two feet high to ten feet high. Depending on the size and shape of your frame, you may need more than one plant to fill the form.

The best time to trim boxwoods used in topiaries is in the spring before new growth begins. Train smaller branches to conform to the structure and prune larger branches to prevent them from growing toward the outside of the form. As the seasons pass, your boxwood shrubs will take on the shape of the structure and you will have a unique conversation piece and interesting focal point for your garden.

Pruning Boxwood Shrubs

Think about stately English gardens with perfectly trimmed hedges or even mazes. You can get that effect with boxwood if you place multiple plants in a line and close together; the result is a solid, rectangular hedge shape. Space boxwoods a little further apart and you can prune them into balls or taller shapes with some space between. You won’t get an instant hedge, but the plants will look neat and green all year and eventually form a hedge.

Of course, you don’t have to make boxwood into a hedge. Simply add a few of the plants to your landscape for the evergreen color and texture and then prune them for shape. I have a Southwestern-style home and mostly native and xeric plants, but the boxwood by my front door is a year-round, neatly shaped welcome for visitors. Boxwood can fit into nearly any landscape plan.

Boxwood Pruning Tips

  • First, gently prune your new plants slightly as soon as you put them in the ground, so they will begin to grow in the shape and direction you like.

  • Prune boxwood each year in spring; it is okay to touch up the plant’s shape or straying branches throughout mid-summer.

  • Be sure not to prune and shape your boxwood in late summer or early fall. When you prune the plant, you encourage the cut branches to grow. They might not recover from the cut in time for winter. I have spotted browned leaves in the past when I trimmed stray branches too late in summer.

  • When you prune boxwood, tiny branches and individual leaves drop from the plant. The delicate cuttings can be a little tough to sweep or rake up. My plant adjoins a gravel walkway, so I always lay down an old sheet to catch the droppings. When done pruning, I can pull up the corners and dump all the clippings in the garbage or compost bin at once. You also can use a tarp, plastic dropcloth or compostable paper to catch the clippings.

  • If growing boxwood as a hedge, avoid trimming on the side between plants. Try to keep each plant slightly larger at the bottom, at least until you go back to even branches and touch up.

  • When using hand shears on your boxwood, begin at the top and cut all the stray branches and make a fairly even line or circle along the top, front (and sides if not part of a hedge). I always go back and hand trim to catch boxwood branches I miss or just to straighten up the shape.

  • If you have a large boxwood hedge to tackle, you can use electric- or gas-powered shears to save time, but hand shears and pruners make cleaner cuts.

  • Mostly, keep up with your once-yearly boxwood pruning and the plants will hold their shape. It is much easier to prune for shape and health oce a year than to try to revive a shrub that is overgrown.

Trimming Boxwood Shrubs With Winter Damage

Although these bushes are evergreen, sometimes boxwood can get winter burn. Those leaves and branches are not very attractive and it is best to cut them off. Do so in early spring for best results. Use pruners for more precise cuts and large shears for bigger branches.. Cutting the dead parts can allow the plant to put energy towards the living part, and help the plant look better.

There is a reason boxwood was the most popular shrub in America in 2018. Use these tips to prune your beautiful boxwood once a year and you will love the results.

Carol Asked

When can I prune boxwoods?

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The Gardener’s Answer

Boxwoods (Buxus) are versatile and can be used in formal or informal gardens. These evergreens do not require annual pruning, but dead or diseased branches should be pruned out regardless of the time of year. Older plants with dead lower branches will benefit from being thinned. This will allow more light and air to move through the plant.

If you are creating a topiary or pruning to thin, shape, or rejuvenate, the best time to do this is late spring/early summer after they have finished putting on new growth for the season. Pruning too early in the spring while they are putting on new growth is fine, but it will only encourage more growth. So, if you do prune too early you may have to get your tools back out later in the season.

The only time you want to avoid pruning these evergreens is during the late summer/fall. Prompting new growth at this time of the year will make the plant more susceptible to winter damage, since the tender growth may not have time to harden off before the cold temperatures arrive. As with any pruning job, make sure that your tools are clean and sharp. Sit tight for now and put this on your to-do list for next summer.

Have a question for the Gardener?

How to Make a Topiary

At some point while strolling through your neighborhood, you might feel the urge to make your landscaping look even more impressive. Your existing shrubs and bushes? They’re fine, but they could be so much more.

It makes sense that you would feel that way. Well-maintained landscaping can increase a home’s resale value by 5-12%.

What you’re feeling is a call to an art that dates back to the Roman empire: topiary.

You don’t have to be a landscaping professional to practice this art. All you need are some shrubs, some good tools (such as a hedge trimmer), and a commitment to maintaining your plants’ shapes for the long run.

The result can be satisfying and fun.

What Is a Topiary?

Topiary is the art of trimming shrubs and hedges into carefully planned decorative shapes.

Have you ever seen a shrub trimmed into a ball shape? What about a hedge sculpted in the shape of an animal? As different as they are, they’re both topiaries.

Indoor topiaries use small perennials and fall into three categories:

  • Pruned topiary: plants are clipped and trimmed to fit a shape
  • Hollow topiary: vines and stems are trained to grow around a hollow frame
  • Stuffed topiary: similar to a hollow topiary, except the frame is filled with a growing medium like sphagnum moss to create a free-standing display that doesn’t require a pot

Outdoor topiaries can be made with plants growing in pots and other containers as well as with bushes and shrubs planted directly in the ground. The best plants to use for outdoor topiaries are plants that keep their leaves for a year or more, which are known as evergreens:

  • Boxwood (a common choice due to their hardiness; Japanese boxwood is a slow-growing species that requires less frequent trimming)
  • Yew
  • Cypress
  • Rosemary
  • Holly (some species of holly are not evergreen)

Just as there are several kinds of indoor topiaries, there are several techniques for creating outdoor topiaries:

  • Espalier: trees (often fruit trees) are trained to grow with their branches flat against a wall
  • Pleached hedges: branches of plants are interwoven to create a corridor along a walkway
  • Living fence: plants growing close together along a property’s edge are cut to the same height to create a natural boundary
  • Standards: plants with a single main stem or a trunk are trimmed in a decorative shape

Of these types of outdoor topiary, living fences and standards are the kinds that are easiest for homeowners in the United States to create.

They’re also the kinds for which a hedge trimmer (or a string trimmer with a hedge trimmer attachment) comes in handy.

Tools of the Topiary Trade

Many of the tools for shaping shrubs are tools that you would use for your regular yard chores.

You might not think that precise, detailed hedge-shaping would require a powered hedge trimmer. However, a hedge trimmer is useful for cutting away the bulk of a bush at the start of a project and for trimming new growth on large bushes. In fact, renowned topiary artist Pearl Fryar got his start using a gas-powered hedge trimmer!

Besides a hedge trimmer or a pair of long-bladed hedge shears for the big cuts, you’ll need other trimming tools for the cuts that require more finesse:

  • Handheld pruning shears: essential for fine, closeup work and greater control
  • Lopping shears: like pruning shears with long handles; good for cutting hard-to-reach branches
  • Pruning saws: for specific cuts on thick, woody growth

When purchasing pruning shears and lopping shears, look for scissor-style blades that provide a clean cut. Flat, anvil-style blades will crush your stems and branches, making cuts that take longer to heal.

In addition to your trimming tools, you’ll also need safety gear:

  • Thick gloves to protect your hands from cuts and scratches
  • Safety glasses to shield your eyes from debris
  • Hearing protection if you’re using a powered trimmer
  • A hard hat if you’ll be working on tall plants and making overhead cuts

First, you should consider your timing. Some experts recommend starting your topiary project in early summer for a few reasons:

  • You’ll avoid cold-weather frosts that could damage newly cut branches
  • You won’t interrupt your plants’ spring growth
  • You’ll be less likely to cut growth that has begun hardening off and turning woody

Pruning late in the day or on a cloudy day is also recommended, as sunlight can scorch freshly cut growth.

After you’ve made any rough cuts with a hedge trimmer or hedge shears, you can begin working toward the shape you have in mind, including some of the most common shapes:

  • Cone
  • Sphere or ball
  • Spiral

Tips for Creating a Cone-Shaped Topiary

The cone is an excellent choice for a first hedge-shaping project. It works well even for plants with lots of irregular branching stems.

To create your cone, start with your shears or trimmer at the top of the plant and make an angled cut downward so that the base will be wider than the top.

If your plant is taller, you can give yourself guidelines to follow by leaning poles or broomsticks against it. Nestle each pole within the branches until it leans at the angle you want.

From time to time, step back and look around the plant to keep the angle similar along all sides.

Tips for Creating a Ball-Shaped Topiary

Although a spherical shape is also good for plants with lots of branches, the “ball-on-top” shape is best for trees with a trunk or plants with a single stem that’s easy to find.

If choosing the ball-on-top shape, prune all the branches away from the bottom of the trunk, leaving several inches of green growth at the top (the exact amount depends on the total height of your plant and the aesthetic you prefer).

If shaping a multi-stemmed bush into a ball, no preliminary pruning is needed.

Start at the top of your plant with your hand shears or trimmer and cut at a downward, outward angle toward the middle of the plant’s height. The angle should be more gradual than it would be for a cone topiary.

Aim to remove about one inch of growth to start. You can always remove more later.

Trim around the middle of the plant’s height by holding your shears or trimmer vertically. Then, trim the bottom of the sphere by making downward, inward cuts toward the base of the plant.

Don’t forget to even out the top of the ball.

A hoop made of wire that circles the center of the bush like a belt can give you a target to aim for with your shears or trimmer.

Tips for Creating a Spiral Topiary

Plants with one easy-to-find single stem or a trunk are also good fits for a spiral shape. A naturally tall cone-shaped plant works best. You can also use the technique mentioned above to shape your shrub into a cone first.

Starting at the top of your plant, wrap string or masking tape around the plant in a spiral, stopping just before the bottom to leave your plant a ring of green growth at the base. Experts recommend three to five turns for plants used in home landscaping.

Adjust the string’s position to create even spacing between the arms of its spirals.

To make your first cuts, start in the middle of your tree’s height and work toward either the top or bottom.

Use your hand shears to make shallow cuts along the length of your string. This will start to create the open space in your spiral.

Once you’ve cut along the entire length of string, remove the string and make further cuts into the groove to open the space. You can cut all the way back to the trunk, or you can keep your cuts shallow, depending on your preferred look.

After you’ve created the open spaces in your spiral, give the green, growing parts a rounded appearance by cutting at an angle along the top and bottom edges.

Frames for Creating Topiary Shapes

For more difficult shapes, or for help creating the standards above, consider purchasing or making a wire frame to guide you.

You can make your own frames for basic shapes by shaping wire around other objects:

  • Shipping boxes for a cube frame
  • Exercise balls or beach balls for a spherical frame
  • Safety cones for a conical frame

You’ll place the frame over your plant and make your cuts just outside it.

Taking Care of Your Topiary

Shaped shrubs don’t always look impressive right away. Often, they need seasons to grow into their forms. Be patient, and remember to look after your topiary:

  • Water it right after you create your shape
  • Continue to water it frequently, since topiaries dry out easily due to the large number of cuts, but don’t flood it
  • Fertilize it the same way you would any other shrub on your lawn
  • Prune it twice a year: once around late May to mid-June, and again in early autumn
  • If you can’t wait until late spring for the first pruning, prune just before the growing season starts (for many, late March)

Also, don’t forget to clean your tools with isopropyl alcohol before putting them away. Clean them and wipe them dry between plants as well. This helps prevent the spread of plant diseases.

Topiary requires care and time. However, once you’ve finished, you can stand back and admire your work, knowing not only that you worked hard on your landscaping but also that you created something striking and distinct.

If that isn’t the mark of an artist, what is?

NEXT: Best-Selling and Top-Rated Hedge Trimmers

Pruning Big Boxwoods — When & How

Photo: Steve Bender

Faithful reader, Gail, asks, “What is the best way to cut back or prune two very large boxwoods that are on each side of our church entrance steps? They are at least 6 feet tall and 6 feet wide. They are very old and we don’t want to get rid of them.” Other readers want to know how to prune big boxwoods at their homes. As always, Grumpy has the answer.

Boxwoods can be pruned any time but late summer and early fall. This is because pruning then will spur new growth that won’t harden off in time for winter and be killed by the cold. Severe late summer pruning followed by a cold winter could even kill the entire shrubs.

Of course, the best way to avoid having to cut back overgrown boxwoods is not to let them get overgrown in the first place. Most types grow slowly, so one pruning a year keeps them in bounds. You can do this with hand pruners or shears. Also remove any dead branches at this time as well as plant debris that accumulates in the center of the shrubs.

You’ll notice that the magnificent boxwoods shown above at Montrose, the garden of Nancy Goodwin in Hillsborough, North Carolina, haven’t been sheared. They’re the result of a painstaking practice called “cloud pruning” performed with hand pruners. New growth is nipped back and then small branches are removed from the insides of the shrubs to create openings between layers of foliage. The end result looks a bit like a cumulus clouds. Opening up the bushes this way gives a natural look and increases penetration of sunlight and air to the centers. Healthier bushes ensue.

However, what if your boxwoods have gotten monstrous — too big for hand pruners — and you need to cut them back beyond the outside foliage so you can walk freely up the steps or see out of a window? This calls for drastic, but necessary, action.

Put away the hand pruners and shears. You need loppers. Cut back the main limbs as far as needed to solve the problem. But try to maintain a rounded, mounded look. Don’t cut the bushes into boxes.

Yes, many of the branches will then be leafless. And if you do this in winter, you’ll be staring at nekkid branches a long time. So Grumpy suggests waiting until spring. The shorter, nekkid branches will quickly clothe themselves in new foliage.

Crepe Murder 2016

Image zoom emFirst, do no harm./em

Crepe Murder 2016 officially kicks off February 1, 2016! Entries will be accepted from then until Tuesday, February 16. This gives you plenty of time, including a long weekend, to creep silently around your neighborhood, smart phone in hand, and take photos of horribly butchered trees like the one above. Email your photos to [email protected] with “Crepe Murder 2016” in the subject line. Start looking!

In the topiary world, Jake Hobson is a bit of a rock star. The Dorset, England–based topiarist originally studied at the Slade—London’s premier art school—before a trip to Japan in 1997 that set him on a greener path. Intrigued by the fanatical approach to pruning in Japan, he returned for two years and worked at a tree nursery in Osaka. When he returned to England, he brought his newfound techniques with him, working first at Architectural Plants in Sussex where he continued to refine and develop his cloud pruning work. He now owns and runs Niwaki, which specializes in Japanese tools and accessories, and while a bad back prevents him from taking on professional topiary clipping anymore he continues to teach through workshops and lectures, as well as looking after his own— and his mother’s—collection of neatly clipped forms. We asked him to get the perfect boxwood shapes.

1. Cut at the right time.

Above: Photograph courtesy of Niwaki.

Boxwood will put on major growth throughout May—sometimes around six inches (“Everyone thinks it grows slowly but actually it grows quite quickly for what it is,” says Hobson), which is why the traditional time to trim it is in early June. Cut earlier than this and the plant will continue its growth spurt and you will need to do another summer cut. In big gardens where there are different types of topiary to clip, this is traditionally followed by trimming evergreens such as Portuguese laurel or bay in July and August and then yew in September. For Hobson, a crisp finish after this June pruning is what that sets boxwood apart in the garden. “For the English and certainly the Belgians, this really tight clipping is what makes box so useful. It gives that sharp focus in a summer garden full of fluffy loveliness.”

2. Keep tools razor-sharp and totally clean.

Above: See more at DIY: How to Clean and Care for Garden Pruners. Photograph by Erin Boyle.

Like other topiary pros, Hobson keeps a bucket of water alongside him as he cuts, occasionally dipping sheers into the water to stop the blade from sticking, but with boxwood he will add a glug of bleach to the water to ensure that it sterilizes the blade. “And if I was in a garden where I was at all concerned about blight, I would clean tools between each plant, too,” he adds. “When I do a workshop and everyone has their own shears, the first thing I want everyone to do is to clean them.” Keeping tools very sharp will also help to decrease the chance of disease.

3. Refine your technique.

Above: English boxwood tamed and topiarized, through judicious pruning. Photograph by Britt Willoughby Dyer.

“When pruning, it’s really about head, hand, shears, and getting into the groove and rhythm of it,” says Hobson, who says the one thing to avoid when clipping topiary is to make big erratic movements—small and steady will help you refine a shape. When cutting curves or balls, use the shears so that the blade curves around the plant and on straight surfaces use the flat side of the shears. Hobson uses Japanese Pro Topiary Clippers (£109) for really detailed work and also keeps secateurs on hand to cut back thicker stems that could damage the blade of the shears. As with most jobs, the best tools make this task so much more enjoyable.

4. Tidy up.

Above: See more of these boxwood topiaries at Garden Visit: Charlotte Molesworth’s Topiary Garden. Photograph by Clare Coulson.

Be sure to clear up all clippings as you work (lay down a sheet underneath the plant and then it’s easy to scoop up once you’ve finished). But it’s a good idea to try to remove dead foliage from inside the plant too. For this Hobson uses a blower on a reverse setting which will suck up all the brown leaves. It may also take some topsoil away too, so add a layer of compost around the plant after you’re done.

5. Prevent disease.

Above: Photograph by Clare Coulson.

As usual in the garden, the best way to keep pests and diseases at bay is with prevention rather than cure. Hobson ensures that there’s good aeration around the plants. If you have lots of herbaceous perennials around box, they can reduce air flow so try to keep a channel of air around each plant. And if you do spot any disease such as blight deal with it right away. Hobson suggests a severe cutback to remove all diseased foliage.

6. Don’t kill your plants with kindness.

Above: Photograph by Britt Willoughby Dyer.

Overfeeding can be a real problem, says Hobson. Plants will put on lots of lush growth, which will look lovely. But this vigorous new growth can be more susceptible to disease. A traditional winter mulch around plants is probably plenty or, failing, that drench plants every month in the growing season with a liquid seaweed solution. (Of course, unless you have poor soil plants probably don’t need to be fed at all.) “Walk around a hillside in the south of France where box is a native; no one ever feeds it there,” says Hobson, who doesn’t feed plants at all in his own garden. “These plants actually do quite well on a lack of attention.”

Above: Some of Jake Hobson’s freshly clipped boxwood topiaries, Photograph courtesy of Niwaki.

See more tips for care and pruning at Boxwood: A Field Guide to Planting, Care & Design and some of our favorite evergreen alternatives to box in our curated design guide to Shrubs 101, including Yew, Rosemary, and Privet. Read more about boxwood:

  • English Boxwood: Is It Worth It?
  • Gardening 101: Boxwood
  • The English Gardener: Just a Little Off the Sides, Please

Green all year long, boxwood draws back to the elegance of French gardens. Along edges to organize the garden, or sculpted as as a standalone shape, it is currently making a comeback.

For a time reserved to the topiary ornaments of castles, boxwood now plays a part in all possible settings. It is often grown in pots, trimmed into clear-cut balls that decorate balconies of city-dwellers craving for greenery. One must state the facts: on top of staying radiant all year round, boxwood resists air pollution very well.

In a garden, it can mark the edges of walkways, surround flower beds and vegetable patches, and even dance along a lawn shaped in varied silhouettes: ball, pyramid, obelisk, spiral… It grows beautifully paired with heirloom rose trees, clematis, honeysuckles and light-blooming flowers like lavender.

Trying Topiary

What makes boxwood so well suited to topiary creations is its dense evergreen foliage and its slow growth, around 4 inches (10 cm) a year. This slow growth explains why shaped boxwood is often so expensive: 5 years are needed to produce a ball and up to 10 for a pyramid!

Unless you are very patient, it makes sense to splurge for a boxwood plant that is already a few years old and well on its way to looking like the shape you want. That way, all you’ll have to do is a bit of maintenance pruning at the end of winter and summer. On a balcony, remember to rotate the pot regularly for even growth.

If you’re looking to sculpt your own specimen yourself, take note that a round ball is easier to trim than a straight line. Ready a template from a piece of cardboard with a half-circle cut in it, or rods and string, to guide your shears. If you’re ready for a more challenging eccentric shape, you can find animal-shaped mesh wire that you can slide your boxwood in, cutting whatever sticks out.

Proper care for boxwood

Boxwood does well in any type of soil, as long as it drains well. Set it up in spring or fall, part sun, and mulch in summer. If it marks a low-lying edge hedge, plant your boxwood specimens near one another, about 8 inches (20 cm) space between them, to cover the entire line even though their growth is slow.

In pots, plant it in a blend of one part garden soil, one part soil mix and one part sand. Water regularly and add fertilizer in spring.

  • Read also: Growing, pruning and caring for boxwood
  • Treatment: Fighting against boxwood tree moth

Laure Hamann

Image credits: Jardiland, La Plante du Mois

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