How To Grow And Care For Boxwoods

Shrubs with versatility and sculptural qualities.

Boxwoods are shrubs with small, dense, evergreen leaves that have a versatile and sculptural quality. Coax them into decorative topiaries, shape them into tall, thick hedges that hide and protect, or use them as low parterres that organize a garden. The boxwood has been a staple of fine gardens for millennia, spanning from the formal hedges of ancient Egypt to the palatial gardens of Greece and Rome to the tidy landscapes of Colonial Williamsburg. 

Boxwoods are now available in various species and selections, making it easy to customize your choice to fit your preferences. Once established, boxwoods are relatively low maintenance. However, boxwoods are toxic to people and pets despite being easy to maintain.

Plant Attributes

Boxwood Care

Plant boxwoods in well-drained soil with a lot of organic matter. Loamy soil or sandy conditions is best. Most boxwoods prefer some shade, but some varieties handle full sun exposure better than others. To minimize bronzing of leaves in the winter, avoid spots that get a ton of afternoon sunlight from the southwest and plant during periods of extreme heat.

Protect boxwoods from strong winds because it has shallow roots. Fertilizing is seldom necessary, but water weekly during the first year of establishment. Mulching can protect the shallow roots from extreme heat, and heavy rainfall will require less watering.

Light

Plant boxwoods in full sun to partial shade or in containers that can move during the harsh afternoon sun. In full sun areas, plant boxwoods under foliage for filtered light and protection.

Soil

Soil type is less critical than well-draining soil. A sandy or loamy consistency is preferable for many boxwoods. Don't allow boxwoods to sit in soggy water because it will lead to rot and disease. Container plants should contain plenty of drainage holes. Soil pH can range from slightly acidic to slightly alkaline, somewhere between 6.8 and 7.5.

Water

During the first few years of establishment, water weekly to give plants at least an inch through watering or rainfall. Water the deepest roots and increase watering during the summer, but allow plants to drain thoroughly before watering again. Use your hands to feel the top few inches of soil to know if it is time to water. After establishing, boxwoods need water about once every two to four weeks.

Temperature and Humidity

Ideal temperature conditions are between 60°F and 80°F for boxwoods. These plants die back during the winter but are relatively tolerable to cold and high temperatures. Growing boxwoods in containers help to introduce more gradual changes in climates with large temperature fluctuations. These plants remain green throughout the winter and are versatile throughout the year.

Fertilizer

Fertilizers with a high nitrogen content are best for boxwoods. Because of the shallow roots, use a diluted or water-based fertilizer, so they do not burn. Add an all-purpose fertilizer before new growth in the spring, and continue use throughout the growing season if necessary for foliage growth.

Types of Boxwoods

Depending on your landscape and climate, several boxwood varieties are available. Other selections work well as potted plants, but all boxwoods add unique foliage and interest to your garden or container plants. Here are some varieties to know:

• 'Wintergreen': Fast-growing shrubs that produce height quickly but need regular pruning.

• 'Morris Dwarf': Slow-growing selection that requires less care but takes longer to reach its desired shape.

• 'Grace Hendrick Phillips': A selection with an extremely-slow growth rate, this boxwood does not require a lot of pruning, making it ideal for a short hedge.

• 'Green Velvet': A hybrid selection with glossy green leaves that tolerate humidity and cold seasons.

• 'Baby Gem': A selection that requires little pruning and is drought-tolerant once established.

Pruning

Prune boxwood plants to encourage a desired shape. This plant has a relatively slow growth rate, so achieving the preferred results can take many years. Work to create an ornamental form during the boxwood's growing season, avoiding pruning during the fall or winter. Cut above the tips of a healthy, green leaf during the spring to ensure new growth.

In addition to its shape, prune boxwoods by removing dead or twisted branches and thinning out the foliage. After a few years of shaping boxwood plants, very little pruning maintenance is necessary.

Propagating Boxwoods

Propagate boxwoods by taking cuttings in late summer or early fall—Choose a hardened or semi-hardened stem from a healthy plant. Here is how to propagate boxwoods through cuttings:

1. Select a healthy branch about four to six inches long and use sterile pruning shears to make an angular cut.

2. Remove lower leaves and place cuttings in a rooting hormone.

3. Fill a container with moistened potting mix of sand, peat moss, and vermiculite.

4. Cover the cuttings with soil and place a plastic bag over the entire container to encourage humidity.

5. Gently pull on cuttings to check for roots, and when established, transplant cuttings to a larger container filled with moist potting soil. Roots develop within three months.

6. Continue caring for plants by keeping them in a sunny spot with moist soil until spring, when you can transplant them outside.

How to Grow Boxwoods From Seed

It is time-consuming to grow boxwoods from seeds, but germination is often successful in moderate climates. After the late chance of frost passes, plant boxwood seeds deeply in a container filled with moist sterile seed starting mix—Ensure there is plenty of drainage in the containers.

Move the container into the refrigerator for at least two months for seed stratification—Maintain moist soil throughout this time. After the seeds begin to sprout, transplant them into new containers to allow the roots to expand. Add organic mulch to the containers and maintain moist soil. Cover the containers with a plastic bag and place them in a sunny location.

After reaching about four inches tall, move plants outside in a shallow hole at least twice as large as the seedling's root system. Plant new boxwoods at least two feet apart.

Potting and Repotting Boxwoods

When potting and repotting boxwoods, choose a container with plenty of drainage holes so the roots will not stay wet, as this causes root rot and other diseases. Add gravel or some other material to assist with drainage. Select containers large enough to support the root systems for a few years, so you do not consistently disturb the plants. A reasonable estimate is selecting a container at least six to 12 inches wider than the plant's root ball.

When transplanting boxwood plants, loosen the root ball by gently squeezing the container and lifting it without damage. Use your hands to separate the roots if necessary. Plant boxwoods with the root ball about one inch below the top of the container and fill it with soil. Gently pack the soil around the root ball and maintain moist soil. Add an organic mulch to the soil to help regulate moisture and drainage.

Overwintering

Mature boxwoods do not require much winter care, but new growth is susceptible to damage. Protect plants from winter burn by wrapping plants in burlap after the first frost. Keep the burlap loose to allow airflow.

Before the first frost, remove damaged, diseased, or weak branches with a sterile pruning shear. Add a layer of organic mulch to help plants retain moisture throughout the winter, but do not cover the plant's base.

Common Pests & Plant Diseases

While blight is something to be aware of, don't let it scare you. Look out for black or dark brown streaks on the stems or rapid loss of leaves. Common boxwoods (Buxus sempervirens) are more susceptible, like the English boxwood. More resistant kinds are available. Some other diseases that impact boxwoods include leaf spots and root rot, but well-draining soil should prevent these diseases from forming.

Some pests that impact boxwoods include nematodes, leafminers, and spidermites. Control pests with insecticides and provide proper care.

Common Problems With Boxwoods

Boxwoods are relatively hardy plants that are easily maintained. However, some common problems occur when growing and caring for boxwoods, so here is what you should know:

Plant Leaves Falling Off

Boxwoods are susceptible to boxwood decline, which is the result of plant stressors and diseases. Boxwood decline, starting with foliage discoloration, will eventually cause the plant to die back. This issue begins with a single branch and spreads over days or weeks. Some stressors include new exposure to sunlight, severe drought, or lack of soil nutrients. Old age and pests can also cause boxwood decline.

Leaves Turning Black/Brown

Boxwoods experiencing freezing weather can cause cold injuries in these plants. Cold injury presents as damaged bark or bronzing or browning foliage. If left untreated, the cold injury can kill a boxwood plant.

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