Boxwood Size Chart: Mature Dimensions by Variety

Boxwoods cover a wider size range than most people expect, from foot-high edging plants to shrubs taller than a one-story house. That means the name on the plant tag tells you far more about final size than the pot it comes in. Most boxwoods also grow slowly, so the plant you choose today is the one you’ll live with for decades.

Boxwood Size Chart by Variety

Each named variety, or cultivar, is a selected form of a boxwood species with its own size and shape. Two plants sold simply as “boxwood” can end up many feet apart in height. The figures below are approximate mature sizes for unpruned plants, given as height by width.

Width matters as much as height, especially for a hedge or a bed beside a path. Mounding types like Korean boxwood grow wider than tall, while upright types like ‘Green Mountain’ and ‘Dee Runk’ stay narrow. A plant listed as “3 x 3” grows about as wide as it is tall, so it usually forms a rounded shape.

Ranges differ between sources. Korean boxwood can vary from 2 to 7 feet tall and spread up to 10 feet wide.13Virginia Cooperative Extension. Selecting Landscape Plants: Boxwoods Some growers list Japanese boxwood at up to 8.5 feet tall and 10 to 15 feet wide.14NC State Extension Plants. Buxus microphylla var. japonica When a range is given, space and site for the larger number.

Sizes depend on climate, sun and soil, which is why nurseries quote ranges. Check the variety name, not just “Japanese” or “English,” before buying.

To shortlist varieties, start with the width you can spare rather than the height. Cross off any variety whose upper listed height and width exceed your space, then choose among what’s left by shape: mound, ball, or upright cone.

Choosing a Boxwood Size for Your Space

For low edging and borders, dwarf English boxwood’s slow growth to 1 to 2 feet suits paths and flower beds.15Monrovia. Dwarf English Boxwood ‘Nana’ is also resistant to pests and diseases, a plus for long low hedges.16The Spruce. 20 Types of Boxwood Shrubs for Landscaping

For mid-height hedges and foundations, Japanese boxwood’s dense growth suits hedges, borders and foundation plantings, even in partial shade.17Perfect Plants Nursery. Japanese Boxwood Shrub ‘Green Mountain’ adds upright structure while keeping a manageable size.18Patuxent Nursery. Green Mountain Boxwood

For tall narrow screens, ‘Dee Runk’ suits living fences and privacy hedges where patios, driveways or property lines are close.19Garden Goods Direct. Dee Runk Boxwood Taller varieties are the better choice for spiral or tiered topiary, while small ones can be sheared into balls or simple shapes.20Monrovia. Boxwood Size Chart: Mature Dimensions by Variety

Next to a house, compare a variety’s mature height with your windowsills. A shrub that will end up taller than the sill will keep needing trimming to keep the glass clear. Leave a gap between the wall and the plant’s mature width, roughly half that width, so air moves behind it and you can reach it to prune and clean up leaves.

Winter matters too. Korean boxwood is among the hardiest, surviving to Zone 4 (about minus 30 degrees Fahrenheit), which makes it a common pick in the coldest regions.21Virginia Cooperative Extension. Selecting Landscape Plants: Boxwoods Its leaves often turn yellowish-brown in winter, which is normal color change for the variety, not a sign of a sick plant.22Nebraska Extension in Lancaster County. Boxwood Size Chart: Mature Dimensions by Variety ‘Wintergreen’ holds green color through winter, so it suits front-yard spots that are seen year-round.23NC State Extension Plant Toolbox. Buxus microphylla Compare your hardiness zone with the zone range on the tag before you buy.

How Fast Boxwoods Grow

Most boxwood varieties add about 3 to 6 inches of new growth a year.24Proven Winners. Boxwood – The Ultimate Growing Guide from Proven Winners Dwarf types may add only half an inch to an inch a year.25Proven Winners. Boxwood – The Ultimate Growing Guide from Proven Winners Japanese boxwood grows less than 12 inches a year.26Perfect Plants Nursery. Japanese Boxwood Shrub

Among named varieties, ‘Wintergreen’, ‘Winter Gem’ and ‘Sprinter’ can add 4 to 6 inches a year,27Pretty Purple Door. Boxwood Growth Rate By Variety and ‘Dee Runk’ adds about 3 to 6 inches.28Pretty Purple Door. Boxwood Growth Rate By Variety ‘Morris Dwarf’ and ‘Morris Midget’ add only about half an inch to an inch.29Pretty Purple Door. Boxwood Growth Rate By Variety

Listed mature sizes describe old plants, not ones a few years in the ground. Korean boxwood, for example, takes about 25 years to reach 5 feet unpruned.30Nebraska Extension in Lancaster County. Boxwood Size Chart: Mature Dimensions by Variety

To estimate how long your planting will take to fill in, divide the gap between the plant’s size at purchase and its mature size by its yearly growth. Treat the result as a rough guide, because growth varies with sun, soil, water and pruning.

With a slow variety, a small starter plant can take about a decade to knit into a hedge, so larger, more expensive plants can pay for themselves in saved years. Faster types such as ‘Wintergreen’ fill in within a few seasons, so cheaper small plants are usually fine.

Spacing Boxwoods by Mature Width

Boxwood roots are shallow and spread sideways rather than going deep.31The Martha Stewart Blog. Planting a Boxwood Border Neighbors therefore compete for the same top layer of soil. For a border, plant about 2.5 feet from center stem to center stem.32The Martha Stewart Blog. Planting a Boxwood Border

Adjust from there by variety. Plant closer than the mature width for a solid hedge that joins up sooner, and farther apart if you want each shrub to keep its own rounded shape. Narrow ‘Dee Runk’, only 2 to 3 feet wide at maturity, can go closer together, while wide Korean boxwood at 4 to 5 feet needs more room. Measure from the center of one plant to the center of the next, not edge to edge, because the shrubs grow outward from their centers.

Keeping a Boxwood Smaller With Pruning

Even big types can be held low: common boxwood can be kept much shorter than 15 to 20 feet by pruning.33NC State Extension Plants. Buxus sempervirens Light yearly thinning, removing select branches, keeps most boxwoods at a desired size while keeping their natural shape.34Better Boxwood. Pruning, Shearing, Thinning – Oh My!

Thinning means reaching in and cutting out branches with hand pruners, 6 to 10 inches on larger plants or a couple of inches on dwarfs.35NewGen® Boxwood. Tips on Pruning Boxwood The gaps let air and light into the plant, which keeps the inner leaves alive.36NewGen® Boxwood. Tips on Pruning Boxwood

Shearing, trimming the whole outer surface evenly, is different. Done again and again, it builds a thick outer shell.37Better Boxwood. Pruning, Shearing, Thinning – Oh My! Inner branches then lose their leaves and the plant becomes a thin green skin.38Better Boxwood. Pruning, Shearing, Thinning – Oh My!

To shrink an overgrown plant, larger, vigorous varieties tolerate hard cutting with loppers or shears.39NewGen® Boxwood. Tips on Pruning Boxwood Leave one-half to two-thirds of the foliage untouched so the plant can recover.40NewGen® Boxwood. Tips on Pruning Boxwood Full recovery may take several seasons, so big reductions are best done over several years.41NewGen® Boxwood. Tips on Pruning Boxwood

A naturally small variety needs less work than a large one kept small by constant pruning. Dwarf types still benefit from yearly thinning to open the center, even though they stay small on their own.42NewGen® Boxwood. Tips on Pruning Boxwood

A potted boxwood can be kept small in the same pot by root pruning rather than moving it up to a bigger container.43Better Boxwood. Better Boxwood Container Planting Guide Lift the plant out and make a few cuts into the root ball, removing a little root mass. Then set it back and add fresh potting soil into the space the removed roots left.

Why a Boxwood May Not Reach Its Listed Size

Winter is a common culprit. Sharp temperature swings can split bark as water freezes in the stems.44Better Boxwood. Winter Recovery: Caring for Cold-Damaged Boxwoods Whole branches can then die back, especially in the middle and top.45Better Boxwood. Winter Recovery: Caring for Cold-Damaged Boxwoods In severe winters in exposed spots, leaves brown and twigs die.46Yard and Garden. Managing Winter Injury to Boxwood Limited damage needs corrective pruning and time to grow out.47Yard and Garden. Managing Winter Injury to Boxwood

Pests and disease play a part as well. Boxwood leafminer blisters leaves, causing yellowing and early leaf drop.48Center for Agriculture, Food, and the Environment at UMass Amherst. Boxwood Leafminer: Landscape: Center for Agriculture, Food, and the Environment (CAFE) at UMass Amherst Plants turn sparse and can suffer branch dieback.49Center for Agriculture, Food, and the Environment at UMass Amherst. Boxwood Leafminer: Landscape: Center for Agriculture, Food, and the Environment (CAFE) at UMass Amherst ‘Peergold’, ‘Cole’s Dwarf’ and ‘Wee Willie’ showed low susceptibility to both leafminer and boxwood blight.50Journal of Environmental Horticulture. Field Performance of Buxus Cultivars and Selections Against Boxwood Leafminer and Boxwood Blight

To tell the causes apart, look at the stems and at individual leaves. Split bark on stems points to freeze damage. Blistered or spotted leaves point to leafminer. Winter browning often shows first on the exposed side of the plant, while leafminer damage is not tied to wind exposure.

To give plants the best chance at full size, offer cool, moist, well-drained soil and some afternoon shade.51cherrylake.com. Japanese Boxwood In marginal zones, shelter plants from winter wind. Where blight is a problem, choose resistant varieties.