When to plant boxwood?

Planting Boxwood: Why You Should Frame Your Garden with Boxwood

Caring for Boxwood

About 115 boxwood cultivars are commercially available in a wide variety of sizes up to about 30 feet. Hedges and herb garden borders are usually dwarf varieties, which reach about 3 feet. All boxwood is evergreen with opposite dark green leaves. Long known to craftsmen for its strong wood, boxwood also has a reputation for low maintenance. Much of the attention boxwood requires can be given in the less-hectic fall and winter months, but a year-round border patrol is recommended. Boxwood is sometimes the only greenery remaining in a winter herb garden. A dense, green year-round standout, it is well worth the long start-up time.

The best time to plant and mulch boxwood is in the fall. In the winter, prune, thin and protect shrubs. Winter protection may be necessary, especially from drying winds and sun exposure. Foliage tends to turn bronze in the winter due to cold and exposure. Remove damaged or dead branches so new growth will fill the vacant areas. The largest selection of boxwood nursery stock is available in spring, which is another good time to plant new shrubs and inspect for insects. In the summer, keep boxwood weed-free and water well.

Jack Roberson breeds award-winning plants, perennials and shrubs. Although he is most recognized as the creator of American daylily ‘Stella De Oro’, Roberson’s recent horticulture venture is breeding boxwood.

“Good choices for boxwood borders are ‘Green Mountain’, ‘Green Velvet’ and ‘Winter Green’,” Roberson says. “All are very cold-hardy and good choices for hedges in (USDA Hardiness) Zone 6. Another good choice for small gardens is ‘Morris Midget’(B.m. var. japonica ‘Morris Midget’) because it is a compact, low-growing mound. Like most boxwood, it will tolerate full sun or part shade.”

Boxwood is susceptible to too much water in the summer and winter. Planting in low-lying areas, or under a downspout, even in the hottest part of the country, is a bad idea. Roberson uses cottonseed meal (a natural slow-release fertilizer) to fertilize his boxwood gardens. Boxwood is hardy through Zone 5 with some protection.

Planting your Plan

Boxwood plants are somewhat expensive. Buying enough established boxwood to outline even a small herb garden can strain any budget. A good way to test your selection before investing in dozens of the same variety is to buy one or two boxwoods and plant them in the garden as a focal point, or purchase four plants to establish the corner posts of your garden. Boxwood planted in containers also can serve to define a garden’s borders. From these few anchors in the garden, make cuttings to multiply the boxwood and establish a garden frame (see “Making More,” Page 18). Cuttings and layering are the best ways to increase your stock.

Plant a few extras when the herb garden border is established. Use these back-up boxwood plants, grown in containers or in another isolated part of the yard, to replace injured or weak plants. Test planting and asking your local agricultural extension office and local herb growers are the best ways to select hardy boxwood that is suited to your microclimate and landscape plan.

Borders While You Wait

Spacing plants and giving them plenty of room to establish roots will prevent overcrowding and reduce disease and maintenance. Well-spaced starter boxwood shrubs may, at first, look lost. If definition is important to you, then consider annuals to fill gaps until the boxwood begins to define your garden.

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Colorful and fast-growing coleus (Coleus blumei) or the deep greens of basil (Ocimum basilicum) will quickly fill spaces between boxwood shrubs until the boxwood grows to fill the frame or border. Both plants can be pinched back or trimmed to form a temporary hedge.

Traditional boxwood borders or knot gardens are not accomplished in a single garden season. The keys to a successful boxwood border or knot garden are time and patience. The efforts are rewarding.

Tips for Maintaining your Boxwood Hedge

Newly planted boxwood needs the care and attention that any newly planted woody shrub or tree requires. Boxwood tends to be deer-resistant and have few insect problems. Insect pests such as psyllids, leaf miners and mites are usually minor problems on well-spaced and pruned plants.

• Boxwood roots like well-drained soils. Root rot is a problem in poorly drained soils.

• Use organic mulch, such as shredded hardwood bark, pine needles and shredded leaf mulch, to control weeds. A 1-inch layer of organic mulch will prevent soil erosion and moisture loss and protect roots. Fertilize with an annual application of rich compost.

• Avoid digging around boxwood’s shallow fibrous root system. Boxwood is easily damaged or killed with too much cultivation in the bordered herb garden or flowerbed. It does not tolerate foot traffic or compacted soil.

• Prune dead or damaged branches to revive growth. While shearing may be necessary on huge estate gardens, most home gardeners will benefit by taking the time to hand prune boxwood, observing signs of stress or insect infestation. Thinning and hand trimming hedges will allow for a denser, hardier border.

Making More for Less

The quickest way to produce a lot of boxwood plants is by taking stem cuttings from a parent plant. The advantage will be progeny identical to the parent plants.

Remove cuttings from 1- or 2-year-old branches anytime from July to December and place into containers filled with simple potting mixes. Take cuttings that are 3 to 4 inches long. Remove lower leaves and place cuttings an inch deep in a shallow container filled with equal amounts of sharp builder’s sand and perlite, or a mix of half pine bark and half perlite. High humidity and good drainage are ideal rooting conditions. Cover with plastic. Water cuttings by misting with a spray bottle. Gradually remove the plastic covering to harden off the plant.

Roots should appear in two to three months. After roots have formed, transplant cuttings into their own individual containers. Little boxwood plants do well in a greenhouse or outdoors in a protected area for two or three years until they are ready to be planted in the garden.

Containing Boxwood

When growing boxwood in containers, use a slow-release fertilizer in the soil mix. Because regular watering and good drainage is necessary in containers, nutrients tend to leach out of soil mix. Do not overfertilize boxwood as the shallow roots are easily burned by direct contact with strong commercial fertilizers. Always use a low concentration of fertilizer, never more than 10-10-10.

Freelance writer and Master Gardener Patsy Bell Hobson recently moved to a 150-year-old home in Cape Girardeau, Missouri. To her delight, the property included an established boxwood hedge that provides a resource for cuttings and mandatory lessons in care, maintenance and pruning.

Boxwood Care – How To Grow Boxwood Shrubs

Boxwood plants (Buxus) are dense, evergreen shrubs often planted in elegant and formal landscapes. Many varieties and cultivars of boxwood plants exist. Boxwoods are grown for foliage as their flowers are insignificant.

Growing boxwood in your home landscape allows you to create a formal hedge, a matching border or a pair of boxwood plants to balance an entryway. Boxwoods may also be planted as focal points or foundation plantings.

Tips for Planting Boxwood

When choosing where to plant boxwoods, make sure to plant them in the spot most appropriate for their needs. A full or part sun location is needed for optimum growth of this specimen. Successfully growing boxwood requires well-drained soil and while the plants prefer soil to be organic, the boxwood’s soil needs are adaptable.

When planting boxwood, consider your year round climate. If temperatures become extremely hot in summer, boxwood plants will appreciate afternoon shade and regular watering. Water deeply, as frequent, shallow irrigation will not reach the root zone of the growing boxwood. Until established, after about two years, boxwoods will need at least weekly watering.

When planting boxwood, locate them in an area that is protected from winter wind to avoid a condition called winter bronzing. Plant at the same level they were planted at the nursery or in the container. Planting boxwood too deeply can lead to stress and possibly death.

Information on Boxwood Care

Properly mulching the shallow-rooted boxwood helps retain moisture and keep roots cool. Growing boxwoods should have a 2- to 3-inch layer of mulch extending 12 inches past the foliage. As with all shrub mulching, trunks should not be covered.

Aside from watering and mulching, growing boxwood is a low maintenance task, unless you wish to keep them as a sheared hedge. Shearing, or pruning of boxwood, is the most time-consuming part of boxwood care when they are grown as a hedge, but you will be rewarded with a healthy, long-lasting hedge. Older boxwood care will include thinning limbs to allow sunshine to reach the inner foliage.

The boxwood leaf miner is the most common pest one must deal with when caring for boxwoods. If foliage begins to yellow, treat with organic oil or insecticidal sprays. Phytophthora root rot may result from soggy soils.

Yearly soil tests can determine if the soil pH for the boxwood is correct. Soil pH should be between 6.5 and 7. It is best to test the soil before planting boxwood. pH can be raised with the addition of lime and lowered by sulfur.

As slow-growing landscape, boxwoods are valuable plants, and consequently they are expensive. Take time to choose where to plant boxwood carefully. Remember to water and mulch properly for a long-lived, vigorous specimen.

Gardening FAQ

Boxwood (Buxus) is a very versatile and useful evergreen shrub that can be used as edging, hedges, screens and specimen plants. It will grow in full sun but prefers a slightly shaded location. As long as the ground is not too compacted, boxwood will thrive in many soil types. In areas with acid soil, lime should be added to raise the pH to 6.8-7.5. Soil should be well drained, as boxwood won’t tolerate waterlogged conditions. A 2-3-inch layer of mulch helps keep the plant’s shallow roots cool and moist. Amending the soil with compost will condition it as well, which enables the plant take up the nutrients it requires.

The most common problem encountered with boxwood is browning (bronzing) of the leaves in winter. This can often be prevented or reduced by planting the shrubs in a partly shaded site protected from winter winds. An alternative is to provide protection with a screen (e.g. burlap) or, if the shrubs are small, cover them with evergreen branches. Bronzing does not harm the plants; they will grow back green in the spring. Keeping the shrubs healthy will also help prevent bronzing.

A number of insect pests, particularly boxwood leafminer, can be a problem and should be treated. English boxwood (Buxus sempervirens ‘Suffruticosa’) is susceptible to a fungal disease known as “boxwood decline.” Again, healthy plants in a proper growing environment are less susceptible.

Growing boxwood

If you need to raise the pH of your soil, dolomite lime (calcium carbonate or calcium magnesium carbonate), with its low oxide content, will maintain an elevated soil pH for longer period of time than quicklime (calcium and magnesium oxides) or slaked lime (calcium and magnesium hydroxides). Some shade, up to about 20 percent, reduces both summer scald and winter injury. Shade also reduces mite damage, as does summer irrigation. Do not overfertilize. Do not prune when the temperature is below 40°F for several weeks.

Pruning boxwood

The preferred time to prune boxwood (Buxus) is late winter or early spring in the northeast. Boxwood takes to shearing and shaping quite well. Propagation can be done in late summer or early fall.

Preventing foliage diseases of English Boxwood

Mature English boxwood is prone to developing overly dense foliage, often with fatal results. The dense growth reduces sunlight into the center of the shrub, which causes premature foliage drop, weakening the plant. The resulting leaf debris accumulates in the lower branches, causing abundant and vigorous aerial roots to grow in this moist and dark environment. Eventually, the exposed aerial roots will die, shocking the weakened plant.

When planting, give each plant room for sunlight and good air circulation. Thin English boxwood in late fall if the foliage completely hides the view of the interior branches. To thin, using sharp bypass pruners, reach inside about 6 inches, and remove a twig. Continue to prune until the small interior twigs become intermittently visible, along with the older, light green interior leaves. When pruning is completed, the shape and size of the boxwood should look unchanged. Use clippings for propagation if desired.

Species and varieties to grow

The most commonly grown boxwoods are the common, or American, boxwood (Buxus sempervirens) and the English or dwarf variety. However, there are about 70 species of boxwood growing worldwide, and many cultivated varieties have been developed.

Common boxwood grows to a large shrub or small tree (to about 25 feet) but it can be easily pruned to any height or shape. The variety ‘Vardar Valley’ is among the hardiest of B. sempervirens cultivars available and retains its green color well in winter. It has a broad, spreading habit, and reaches a height of 6-7 feet.

The English or dwarf variety ‘Suffruticosa’ is also hardy to about Zone 5. It is a low-growing, compact shrub, rarely growing over 3 feet. It is often grown as an edging plant and in parterres. It is, however, very disease-susceptible.

B. sempervirens ‘Graham Blandy’ is fastigiate variety that grows to 6-8 feet but only 15 inches wide. It will make a fine vertical accent in the garden.

The Korean boxwood (B. microphylla var. koreana) is a hardy variety that grows slowly to a height of 1.5-2 feet.

B. sinica var. insularis ‘Wintergreen’ is also known as Korean boxwood. It is hardy to Zone 4 and grows to 2-4 feet in a spreading shape.

‘Green Mountain’ boxwood is a hybrid between B. sinica var. insularis ‘Wintergreen’ and B. sempervirens ‘Suffruticosa’. It’s a dense, upright variety that can eventually grow to 5-7 feet tall.

It is worth noting that boxwoods are relatively deer resistant. They have a characteristic scent that some people find objectionable.

For tips on a variety of gardening topics, see our Plant Information Guides.
– Courtesy of NYBG Plant Information Service

How to Care for Boxwood

By Kimberly Toscano

Boxwood is beloved for its versatility in the landscape. A strong form and bright evergreen foliage provide structure and color throughout the year. Whether you prefer your boxwood clipped and formal, or rustic, these care tips will help you keep boxwood looking great all year long.

Get Off to a Good Start

Siting boxwood in the proper location goes a long way toward maintaining healthy plants. Think about the conditions in your garden throughout the year. Are your summers hot and dry? Are winters windy or calm? Boxwood performs best in full sun to part shade conditions. In hot climates, plants benefit from afternoon shade. Boxwood is susceptible to damage from dry winter winds; plant in a location where it will be protected.

Provide Adequate Drainage

Boxwood plants tolerate a variety of soils, whether acidic or alkaline, rich or infertile. The one essential soil requirement for a healthy boxwood is good drainage – these plants do not tolerate wet feet! Amend soils with organic matter or plant on a berm to improve drainage.

Avoid wet areas, such as alongside downspouts or low-lying portions of the landscape. Boxwood are also commonly planted in containers. Be sure to select a container with excellent drainage to avoid root diseases.

Protect Those Roots

Boxwood plants have a shallow root system that can easily dry out. The first step to maintaining a healthy root system is planting at the proper depth. Set plants such that the root ball sits just an 1/8 inch above the soil surface. This will allow plants to settle properly without becoming too deep.

Provide a two- to three-inch layer of mulch to keep roots cool and conserve soil moisture. Extend the layer of mulch at least one foot beyond the canopy of the plant. In fall and spring, rake away any fallen leaf material to control disease organisms and replenish mulch as needed to maintain good cover.

Prune by Thinning

Throw away those shears! Today’s diverse selection of boxwood varieties like Baby Gem™ offer compact growth and dense branching without the need for heavy shearing. These new selections are healthier than maintaining rounded forms through shearing – a practice that can encourage disease by shading plant interiors, weakening branches, and reducing airflow. Instead of shearing, thinning is the recommended way to prune both compact and larger boxwood varieties.

Pay attention to damaged plant material when pruning. Remove broken, dying, or diseased branches as soon as they are noticed. This will assist with reducing disease organisms. Maintain good light penetration to the interior of the shrub by removing some of the oldest branches each year. Be sure to remove any foliage and debris that has collected among the boxwood branches.

Winter Protection

Boxwood foliage can become yellow-orange to reddish brown in winter from drying winds, frost, and intense sun ­– a problem called bronzing. Improved varieties like Baby Gem™ Boxwood hold color well in winter, but some protection can go a long way to avoid bronzing. Protection from winter winds is key to limiting bronzing. If the planting site does not offer protection, burlap wraps or windbreaks may be used to protect foliage.

Also, water plants prior to freezing temperatures to reduce bronzing. Keep roots insulated and conserve soil moisture by maintaining a three-inch mulch layer throughout fall and winter.

Water Wisely

Overwatering is a leading cause of root diseases, while underwatering can promote stress, which makes plants more susceptible to certain pests. What is a gardener to do? Water plants slowly and deeply only when needed.

In the first year, newly planted boxwood will require regular irrigation – weekly or more during hot, dry weather. Second year plants are still developing a healthy root system and will continue to require water if rainfall is inadequate. Once established, boxwood only require supplemental irrigation during dry conditions.

Fertilize as Needed

Every soil is different, and therefore so are a garden’s fertilization needs. Conduct a soil test to take the guesswork out of fertilizing. Proper fertilization encourages healthy growth and can reduce pest problems. Boxwood respond well to spring applications of nitrogen or a balanced fertilizer where phosphorous and potassium are deficient.

Remember, boxwood have wide, shallow root systems and can be damaged by over-fertilization. Apply fertilizer throughout the root zone, extending beyond the crown of the plant. Keep fertilizer from coming into direct contact with foliage, trunks, and roots.

Boxwoods Make Gardens Better

In a formal setting or a casual situation, boxwood is always up for the task thanks to its versatility. In winter this shrub’s strong shape, rich green color, and air of old-world formality dominates the garden, taking center stage. In summer, when the garden is in full-bloom, they meld into the background providing structure, enhancing without competing. While the most familiar forms are what are commonly referred to as “American” (Buxus sempervirens) and “English” (Buxus sempervirens ‘Suffruticosa’) boxwood, there are about 90 species and over 365 different cultivars, including Japanese and Korean varieties. Different boxwood plants and species vary tremendously in size, shape, leaf characteristics, growth rates, and hardiness. The secret to working with these evergreens is choosing the best selection to fit your vision and growing conditions. Here are our top picks and ways to use them.

Hedges:

Because they take well to shearing, boxwoods are ideal for defining different spaces in the garden, as a border along a property line or for a tidy foundation cover-up. (Tip: If you’re looking to achieve a tight, close hedge, pay attention to spacing; place your plants half as far away from one another as the mature width listed on the plant tag and they will fill in nicely.) These three are hardy:

Winter Gem Boxwood

Variegated English Boxwood

Green Beauty Boxwood

Edgers and low hedgers:

Gardeners have been clipping boxwood shrubs into tight formations since 4,000 BC with the Egyptians picked up some shears and went to work. From parterres and knot gardens to defined borders along walkways or beds, low-growing boxwoods such as these three help you play with structure.

Dwarf English Boxwood

Morris Midget Boxwood

Wee Willie® Boxwood

Punctuation point:

Greet your guests at the door with a single or several shapely boxwoods (we love three different staggered heights packed into a tight grouping), use them to define corners in a border, or add to billowing borders for structure. These cultivars make it easy:

Chicagoland Green™ Boxwood

Faulkner Boxwood

Green Velvet Boxwood

Topiary:

Select one of the taller-growing varieties for swooping spiral or tiered ball topiary forms. Smaller varieties can be sheared into whatever shape you fancy, from classic orb to whimsical whatever. Take clippers to these:

Green Tower® Boxwood

Green Mountain Boxwood

Golden Triumph Boxwood

Containers:

Just about every boxwood is a candidate for a container because they look just as good in January as they do in June. Choose a fast-draining pot that is at least as wide and tall as the plant itself and preferably bigger. The larger the container, the more soil it holds and the less often you have to water. This one’s a great container candidate:

Petite Pillar™ Dwarf Boxwood

Keeping Boxwood Happy

Provide excellent drainage: Boxwood is highly adaptable to various soil types, including average or poor soils as well as acidic or alkaline provided the soil is well-drained. Boxwoods can’t take standing water and heavy, wet soil which can lead to root rot. Prevent by amending soil with lots of organic matter and planting high when installing.

Keep it clean: When a boxwood is sheared to produce denser outer foliage, air circulation is inhibited, light is prevented from reaching the inner sections of the plant and dead leaves and stems accumulate in the center of the plant, all of which can promote fungal diseases that can cause potentially fatal dieback. Prune back all dying branches to healthy wood, remove all debris from the center of the plant, and thin out some of the outside growth so that air and light can reach the center.

Exposure: Boxwoods thrive in full sun or light shade, but they don’t like exposed, very windy sites, particularly in winter. Protect boxwoods by keeping them vigorous and healthy, watered as needed in late and apply a fresh layer of mulch in fall to help prevent winter damage.

Fertilizing and watering: Apply a balanced, all-purpose fertilizer (10-10-10) in spring to encourage leafy growth and again in fall to promote root growth. Monthly application of compost tea and use of drip irrigation, which might mitigate blight, can help maintain their health.

Back from the brink: If you have a younger, smaller boxwood that’s not doing well, prune back the dead branches, open up the center of the plant, sprinkle one or two cups of a slow-release fertilizer around the shrub, and water it in. If your plant is older, one of the slower-growing varieties, or taller than 3 feet, the time to recover makes trying to save it impractical. Replace it with a new one.

K-State Research and Extension

Boxwood – A Landscape Essential

Return to Trees and Shrubs Agent Articles

Evergreens are an important part of any landscape, whether they’re used in the front yard or spotted in a garden setting. The standard recommendation is to have at least one-third of the plant material in the front landscape be evergreen. This helps provide for year-round interest and color. Using evergreens in the perennial garden also provides year-round interest and creates what many call the “bones” of the garden — the constant structure needed to provide a garden’s character.

Boxwood is grown throughout the country and is as well adapted as any other evergreen to our ever-changing weather patterns. Boxwood will tolerate full sun to light shade. All it really asks is some extra water during the dry spells once it is established. It also requires good drainage because it will not tolerate wet soil.

A nice quality about this plant is its smaller growth habit, which works perfectly in a number of different settings because it does not outgrow its designated area and become difficult to manage. Many other evergreens grow tall and wide, making them difficult to situate without pruning later.

Boxwood Varieties
Like many other plants, there are numerous cultivars of boxwood on the market which can make it confusing when making your selection. Some will argue that there is a big difference between Buxus sempervirens or Buxus macrophylla, or many of the crossed species, but I believe the differences are minor. But to the discerning person, you will notice varying leaf sizes and slight color differences during the winter months, as some varieties tend to hold the dark glossy green foliage while others have a bronze cast.

The following are a few of the more common varieties on the market and ones that should be added to the landscape:
‘Green Mountain’ – Is the best upright, cone shaped variety on the market. It has nice dark green leaves which may bronze slightly over the winter, and works well to make a statement in the garden with its shape. It will grow 3 to 5 feet high and 2 to 3 feet wide.

Green Tower (‘Monrue’) – Is a narrow, upright right form developing into, as the name implies, a tower, becoming more flat topped. It’s best used as an accent or as a narrow hedge. It will reach 6 to 8 feet with time and stay under 2 feet wide.

‘Green Velvet’ – Is the perfect match for either Green Mountain or Green Tower. If left in its natural shape it will develop into a nice rounded globe shaped shrub, growing to a height and spread of 3 to 4 feet. It also works well in a sheared hedge as a border.

‘Wintergreen’ – May be the most common variety found on the market. This is the industry favorite to grow in 1 gallon containers. They sell for around $5 each as a small plant at box stores. ‘Wintergreen’ is a Korean boxwood which normally has smaller leaves and may tend to bronze during the winter. But overall, it is a nice boxwood. It stays small, 3 to 4 feet tall and wide.

The market will soon be flooded with many new cultivars of boxwood. The industry trend for many of these newer varieties is dwarf, in both overall size of plant and leaf size. These will be a little more pricey once they hit the market. If you have not planted boxwood in your garden take another look, as it truly does deserve a place in the landscape.

Weighing in on Boxwood

Valued by ancient civilizations for its beautiful close grained wood and evergreen foliage, boxwood has acquired legendary status during its 6,000 year history of use. It is one of the oldest plants cultivated by man for ornamental as well as commercial purposes.

The “bones” of the formal parterre garden here at the estate are boxwood, lovingly planted during the 1800’s by Mrs. Sarah Ferrell. We believe that she probably began her garden by rooting plants from shrubs in her mother Nancy’s garden, which was close by. Using primarily Buxus sempervirens ‘Suffruticosa’ (known as English or dwarf English boxwood) and Buxus sempervirens (common boxwood), she designed and created a magnificent terraced landscape reminiscent of a fine European garden. Other species and cultivars of box have been added to the garden over the years, so that now we have at least a dozen types representing at least five different species growing here. Due to both the popularity of boxwood and their prominence in our garden, it is natural that questions are put to us about the culture and care of these shrubs. Following are some of the most common inquiries that we receive along with answers from our horticulture staff for their successful cultivation in most of the Southeast.

Q: Are boxwood difficult to grow?

In general, no they are not. However, boxwood are like most plants in that they perform best where well sited and when their cultural requirements are given a reasonable amount of consideration.

Q: What sort of siting is preferred and what soil requirements are necessary in order for them to thrive?

Although boxwood will grow in full sun, situating them under high shade or where they will receive primarily morning sun and afternoon shade is more ideal. Avoiding exposure to large amounts of winter sun and wind is also advisable. Good soil drainage is a must, and extremely heavy clay or very sandy soils frequently cause problems. The correct soil pH is absolutely critical as boxwood thrive best in neutral soils with a pH from 6.5 (slightly acidic) to 7.5 (slightly alkaline). Due to the fact that soils in the South are typically acidic, we strongly advise having a sample done to test your soil’s pH and then amending to adjust it if necessary. We test the soil in the garden here at least once a year and usually have to apply lime annually in order to keep the soil from becoming too acidic for the boxwood.

Q: What is the best time of year to plant boxwood?

In our experience, fall, and specifically October, is the ideal time for us to plant. The month would vary depending on the part of the Southeast you live in.

Q: What about fertilization?

When we fertilize the garden, a light application of an organic fertilizer is broadcast over the entirety. In other words, we do not fertilize our boxwood separately unless it is a new planting or we observe signs of a nutrient deficiency or stress. We apply it every two or three months—even in the winter, although very lightly then. We also try to put compost around our boxwood once every year or two in order to protect their shallow roots and add humus to the soil. Our recommendation would be to tailor a similar fertilizer regimen for your boxwood if they are incorporated into a garden, as most of ours are. If they are being used as a foundation planting around your home, then fertilizing them individually might make more sense. However, we would still recommend organic fertilizer as well as periodic applications of some compost.

Q: What about using cottonseed meal on boxwood? Isn’t it a popular choice?

Yes, cottonseed meal has long been recommended for boxwood, and it is an excellent organic fertilizer. A warning about using cottonseed meal repeatedly—it will contribute to soil acidity (low pH) over time, which can certainly jeopardize the health of boxwood. Annual soil testing in order to monitor proper soil pH levels would be a must.

Q: How often do you water boxwood?

The answer to that question depends on several factors. As a rule, we like for our established boxwood to receive an inch of water (rain, preferably) about every ten days. We typically have to supplement with irrigation only during the summer. It is just as important for the plants not to be too dry during very cold weather as it is during hot weather, so being aware of rainfall amounts year round is very prudent. Newly planted boxwood, as with most shrubs, require more watering until established. Usually we water recently planted shrubs two or three times per week, particularly during their first spring and summer, depending on rainfall and temperature. Extra watering for newly planted boxwood is continued for a couple of summers, although not quite as often after their first full season of growth.

Q: What about insects and diseases?

Healthy boxwood are not typically bothered by serious disease problems. Siting them properly is more than half the battle in that regard. Also, if they are being sheared regularly, as in a formal garden such as ours, they need to be thinned periodically in order to prevent disease problems from occurring. Thinning involves cutting out small clumps of branches in order to let light and air into the interior of the shrub. The primary insect problem that we encounter is boxwood leaf miner, but not all boxwood fall victim to it. English as well as the many choices of Asian boxwood are quite resistant. However, common box and many of the hybrids are susceptible. The leaf miner’s presence is characterized by small round blisters on the underside of the leaves. If miner infestation is moderate to severe, treatment with a systemic insecticide will likely be necessary to reduce their numbers and control damage.

Q: Could I grow the same kinds of boxwood that you have growing at Hills & Dales?

If you live in the piedmont region you could grow most of the boxwood featured in our garden, including the predominant English and common box. In our opinion, the latter two do not thrive in southeastern zones that are warmer than USDA zone seven. Species native to Asia and their cultivars, as well as some hybrids do very well through zone eight and perhaps even further south. Examples are: Japanese boxwood (B. microphylla variety japonica), Harland’s boxwood (B. harlandii), and several cultivars of littleleaf boxwood (B. microphylla). Some of our favorites are: ‘Winter Gem’, ‘Curly Locks’ and ‘Green Mountain’ which is a hybrid. Several of the hybrids are quite vigorous in hot climates and have more of the Old World boxwood “look” than do many of the Asian ones.

Considered through the ages as garden classics and aristocrats, these shrubs have long had a secure place in the hearts, as well as the property of many southern gardeners. Mrs. Alice Callaway once wrote of those lining the paths and beds here at Hills & Dales as “cherished old plantings of boxwood.” Perhaps that thought, as well as the information we have given, might inspire you to plant this old-time favorite in your garden.

Flickr Creative Commons photo courtesy of The Greenery Nursery.

By Julie Christensen

Boxwoods (Buxus) were first introduced in America from England in 1652. Colonists planted them widely and they still can be found in old colonial gardens throughout the East Coast. With their small, evergreen leaves, boxwoods are most widely used as tightly clipped hedges, but they can be allowed to take a more natural form or clipped into topiaries or balls.

There are three species of boxwoods – English (B. sempervirens), Japanese (Buxus microphylla var. japonica) and American or common boxwood (Buxus sempervirens, L). English boxwood is a true dwarf type, usually remaining under 4 feet tall. It is the most commonly grown species. Japanese boxwood was first introduced in 1890. Cultivars can grow up to 8 feet tall and 20 feet wide. Japanese boxwood is typically grown in the south because it is more heat tolerant than other varieties. Common boxwood is a cold-tolerant shrub or tree that can grow to 20 feet tall or more. All three species thrive in the USDA plant hardiness zones 5 through 8, although some cultivars are more adaptable.

Growing Boxwood Shrubs

Boxwoods are fairly adaptable, but they’ll grow best if you give them their preferred growing conditions. Although evergreen, boxwoods are prone to winter bronzing, especially when planted in an unprotected location. The best spot for them is on the north or northeastern side of the house in partial shade to full sun. Morning sun with a little afternoon shade is ideal.

Boxwoods grow best in light, loamy or sandy soil. They’re prone to root rots in clay soils so amend such soils to lighten them or plant boxwoods in raised beds. Also, avoid planting boxwoods in low-lying areas that tend to stay wet after rainfall. They also prefer a soil pH between 6.0 and 7.5. Amend acidic soils with lime the fall before you plant boxwoods.

Boxwoods grow slowly. Some varieties grow as little as 1 inch per year. These long-lived plants can take as much as 10 to 15 years to reach their mature height. Because of this slow growth, they don’t respond well to heavy pruning. Instead, prune them lightly each winter to remove any dead or diseased branches and to open up the plant, if necessary. If you want a clipped form, trim them with hedge clippers two or three times each season, trimming back only ½ inch at a time. If you’re growing a hedge, make sure the top of the hedge is slightly narrower than the bottom so light can reach the lower portions of the plants.

Fertilize boxwoods in early spring before new growth emerges with about 1 cup of 10-10-10 fertilizer per 100 feet of row. If you have sandy soil, make an additional application in early summer, but don’t fertilize boxwood in late summer. Boxwoods need consistently moist, but not soggy, soil. Water two or three times per week, or as needed, to keep the soil moist 1 inch beneath the surface. Mulch with 2 inches of wood chips or bark to help keep the soil moist.

Propagating Boxwood

Because boxwoods grow so slowly, most gardeners prefer to grow them from established nursery plants. However, you can also propagate boxwoods from cuttings. Cut a 5- to 6-inch piece from a vigorously growing branch. Remove the leaves from the bottom two inches of the stem and place it in a cutting medium such as coarse sand. Keep the medium moist and place the cutting in a sunny location. Transplant it when you notice roots growing from the cutting – typically in two to four weeks.

Problems

The most common problem with boxwoods is winter injury, which causes browning leaves. While this condition won’t kill the plant, it isn’t particularly attractive. Winter bronzing is normal on Japanese varieties, but you can prevent it in other cultivars by placing the plants in a protected location or wrapping them loosely with burlap during the winter. Make sure they received adequate water and fertilizer during the growing season and water them occasionally during the winter if conditions are dry.

Sucking insects, such as aphids, psyllids and spider mites, sometimes infest boxwood. You may notice drooping leaves and honeydew, a sticky substance, on the leaves and ground. Treat these pests with insecticidal oil or an insecticide labeled for their use.

Boxwood decline is a disease that sometimes afflicts English boxwoods. Characterized by slow growth and a gradual decline in health, this condition can be minimized by providing proper growing conditions.

Learn more about the boxwood on YouTube.

P Allen Smith tells you how to care for boxwoods on YouTube.

The United States National Arboretum writes about boxwood.

Julie Christensen learned about gardening on her grandfather’s farm and mother’s vegetable garden in southern Idaho. Today, she lives and gardens on the high plains of Colorado. When she’s not digging in the dirt, Julie writes about food, education, parenting and gardening.

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