Boxwood shrubs, scientifically known as Buxus sempervirens, are a classic choice for any landscape due to their evergreen nature and versatility.
Originally from Europe and Asia, these evergreen shrubs are favored for their dense, upright habit and attractive green foliage.
Boxwoods are well-loved for their ability to thrive in a variety of conditions, from full-sun to partial shade. They are also known for being deer resistant, making them an ideal choice for hedging or as topiaries.
One of the most popular uses of boxwood is as a hedging plant. Their dense growth and ability to be pruned into various shapes make them a popular choice for creating formal garden designs.
The best time for planting or removal is in late winter or early spring, allowing the shrub to establish its root ball before the growing season begins.
However, it’s important to ensure that boxwoods are planted in well-drained soils to prevent root rot. This is a common issue, especially in the case of boxwood shrubs, as they are susceptible to it.
Another common problem is the boxwood blights, a fungal disease that can cause leaf spot and new growth to be affected.
Moreover, boxwood mites and boxwood psyllid are common pests that can infest these shrubs, affecting their health and appearance.
Despite these potential issues, with proper care and attention, boxwood shrubs can be a stunning addition to any garden landscape.
As a master gardener, I’ve had the pleasure of growing and caring for boxwood shrubs for many years. In this guide, I’ll share everything you need to know about growing and maintaining these beautiful plants.
Botanical Name: Buxus spp.
Common Name: Boxwood, English boxwood, box
Family: Buxaceae
Plant Type: Shrub
Hardiness Zones: 5-9 (USDA)
Sun Exposure: Full, partial
Soil Type: Loamy
Soil pH: Neutral, alkaline
Bloom Time: Spring
Flower Color: Green, yellow
Native Area: Europe, Asia
Boxwood Plant Care
Caring for boxwood shrubs, scientifically known as Buxus sempervirens, begins with choosing the right landscape location. These evergreen shrubs thrive in full-sun to partial shade, preferring well-drained soils to avoid root rot.
The best time for planting or transplanting is late winter to early spring, ensuring the root ball is well-established before the growing season.
Regular removal of any diseased leaves can help prevent blights such as boxwood blights and leaf spots, often caused by mites and boxwood psyllid.
Boxwoods are also deer-resistant, making them an excellent choice for hedging or as topiaries, and their green foliage adds a touch of elegance to your garden.
Light
Boxwood shrubs thrive in a variety of light conditions, but they truly flourish in full-sun to partial shade. This means they should receive at least 4-6 hours of direct sunlight each day, but can also handle some time in the shades.
It is essential to note that boxwoods in shadier spots may not display as dense a growth habit as those in sunnier locales. However, in extremely hot climates, giving them some relief from the afternoon sun can prevent leaf scorch.
Whether adorning the landscapes of Europe or the gardens of Asia, these evergreen shrubs will be at their best with the right balance of light.
Soil
Boxwood shrubs thrive best in well-drained soils. These evergreen shrubs are highly susceptible to root rot, a condition that arises from waterlogged or poorly drained soils. Therefore, it’s crucial to ensure that the soil is adequately drained to prevent this issue.
If your landscape has heavy clay soil, consider amending it with organic matter to improve its drainage. On the other hand, if you’re growing boxwood in a container, ensure the pot has drainage holes to allow excess water to escape.
Before planting, it’s also beneficial to check the pH of the soil. Boxwood plants prefer slightly acidic to alkalinity, so adjust the soil’s pH if necessary.
Water
Boxwood shrubs prefer well-drained soils and require a moderate amount of water. During the growing season, these evergreen shrubs prefer moist conditions but can tolerate short periods of drought.
Overwatering can lead to root rot, a common problem with boxwoods, so it’s crucial to ensure that the soil is never waterlogged.
In late winter, early spring, and late summer, when new growth is prevalent, it’s best to increase watering frequency. However, during the dormant winter months, it’s essential to reduce watering as the plant’s water requirements decrease.
Temperature and Humidity
Boxwood does best in a temperamental range akin to its native Europe and Asia. Ideal temperatures for these evergreen shrubs hover between 70 and 90 degrees Fahrenheit during the growing season, tapering down to 40 degrees in late winter and early spring.
However, these hardy plants can withstand temperatures as low as -20 degrees Fahrenheit. As for humidity, boxwood is versatile and can adapt to various levels, provided the soil is well-drained to prevent root rot.
In regions with high humidity, vigilant monitoring for blights and pests like boxwood mites and boxwood psyllid is crucial.
Fertilizer
Boxwood shrubs, known for their dense evergreen foliage, have specific fertilizer needs to support their lush growth.
The best time to fertilize boxwood is in early spring, just as the growing season begins. A slow-release, balanced fertilizer can provide the necessary nutrients for new growth.
However, over-fertilization should be avoided, as it can lead to excessive, tender growth that is more susceptible to pests like the boxwood mite or boxwood psyllid.
Regular application of fertilizer can also help the shrub recover from any diseases such as boxwood blights or leaf spot, and maintain its deer-resistant properties.
Pruning
Pruning is an essential part of maintaining the landscape appeal of boxwood shrubs, best done during the late winter or early spring before new growth emerges.
This helps in shaping the plant’s upright habit and promoting dense growth. Removal of any diseased or pest-infested areas is crucial to prevent the spread of blights, mites, and boxwood psyllid.
Pruning also stimulates the plant’s vigor and helps to maintain its deer-resistant nature. It’s best to avoid heavy pruning during the late summer to ensure the shrub is prepared for the upcoming growing season.
Overwintering
Overwintering boxwood shrubs require special attention. Late winter is the best time to prepare them for the cold season.
Ensure that the area around the boxwoods is free of fallen leaves and debris to prevent potential blights or diseases such as boxwood blights or root rot.
Consider providing a layer of mulch to protect the shallow root ball from freezing temperatures, especially in regions with harsh winters.
If you’re in a particularly cold climate, consider erecting a burlap screen to protect your boxwoods from harsh winter winds and sun.
Also, consider an anti-desiccant spray to shield the evergreen shrubs from winter dehydration.
Types of Boxwood
Buxus Sempervirens ‘Suffruticosa’: This cultivar, also known as the English boxwood, is a classic choice for hedges and topiaries due to its dwarf habit and dense, evergreen foliage.
Buxus Sempervirens ‘Arborescens’: ‘Arborescens’ is a larger variety of boxwood, known for its upright habit, making it an excellent choice for landscape use.
Buxus Sempervirens ‘Monrue Green Tower’: ‘Monrue Green Tower’ is a unique cultivar that boasts a narrow, columnar shape, making it an ideal choice for vertical accents in the garden.
Buxus Microphylla Var. Japonica: This species, known as the Japanese boxwood, is prized for its tolerance of various light conditions, from full sun to partial shade.
Buxus Microphylla Japonica ‘Winter Gem’: ‘Winter Gem’ is a popular variety of Japanese boxwood, lauded for its hardiness and ability to retain its dark green foliage even in the depths of winter.
Buxus Microphylla Japonica ‘Golden Triumph’: ‘Golden Triumph’ is a striking cultivar of Japanese boxwood, featuring variegated leaves that transition from golden yellow in the spring to a rich green in the summer.
Buxus Sempervirens ‘Green Gem’: ‘Green Gem’ is a compact, slow-growing variety of common boxwood, known for its vibrant green foliage and resistance to pests and diseases.
Buxus Sempervirens ‘Green Mountain’: ‘Green Mountain’ is a cold-hardy cultivar with a pyramidal growth habit, making it a favorite for formal hedges and topiaries.
Buxus Sempervirens ‘Green Velvet’: ‘Green Velvet’ lives up to its name with its soft, emerald green leaves and a mounding habit that makes it an excellent choice for low hedges or standalone specimens.
How to Plant Boxwood From Seed
Step 1: Selecting the Right Seeds
When it comes to boxwood shrubs, there are several cultivars of Buxus sempervirens to choose from. Each cultivar has its own unique habit and growing preferences.
Some are more resistant to pests like the boxwood mite and boxwood psyllid, while others are more prone to diseases like boxwood blights and leaf spots.
Step 2: Preparing for Planting
The best time to plant boxwood seeds is in late winter or early spring. Before planting, it’s essential to prepare the soil.
Boxwoods prefer well-drained soils, so if your landscape tends to retain water, consider adding organic matter to improve drainage.
Step 3: Planting the Seeds
When planting boxwood seeds, ensure that they are not buried too deeply. A good rule of thumb is to plant the seeds at a depth equal to three times their width.
This will encourage the seeds to sprout and develop a healthy root system.
Step 4: Caring for the Seedlings
Once the seeds have sprouted, it’s important to monitor the young plants for any signs of disease or pests. Common issues to watch out for include boxwood blights, leaf spots, and mites.
In late summer, you can encourage new growth by lightly pruning the plants. This will help them develop a dense, compact habit which is ideal for hedging or creating topiaries.
How to Propagate Boxwood
Step 1: Choose the Right Time
The best time to propagate boxwood shrubs is in late winter or early spring. This is when the plants are dormant and the temperatures are still cool, which is ideal for root development.
Step 2: Prepare the Parent Plant
Before taking cuttings, it’s important to prepare the parent plant. Prune the boxwood to encourage new growth and remove any diseased or damaged branches. This will ensure that the cuttings you take are healthy and vigorous.
Step 3: Take the Cuttings
Using sharp, clean pruners, take 4- to 6-inch cuttings from the tips of the boxwood branches.
Make the cuts at a 45-degree angle, just below a leaf node. Remove any leaves from the bottom half of the cutting to reduce moisture loss.
Step 4: Prepare the Cuttings
Once you have taken the cuttings, immediately dip the cut ends in rooting hormone to encourage root development. Then, plant the cuttings in a well-draining potting mix, burying them about halfway.
Keep the soil consistently moist but not waterlogged, and place the cuttings in a warm, bright location out of direct sunlight.
How to Pot or Repot Boxwood
Step 1: Choose the Best Time for Potting
The best time to pot or repot boxwood shrubs is in the late winter or early spring, before the growing season begins.
This timing allows the plant to establish its roots in the new soil before the stress of summer heat.
Step 2: Prepare the New Pot and Soil
Boxwood shrubs prefer well-drained soils, so make sure your pot has adequate drainage holes. Fill the bottom of the pot with a layer of soil.
Boxwood shrubs can adapt to a variety of soil types, but they prefer slightly alkalinity. You can amend the soil with lime if needed.
Common Pests and Plant Diseases for Boxwood
Boxwood Blights
Boxwood blights are a serious concern for boxwood shrubs, particularly the common Buxus sempervirens. This disease, caused by a fungus, leads to severe defoliation and can result in the removal of the entire plant.
It’s essential to monitor your boxwoods for early signs of blights, such as dark brown or black lesions on the leaves, and promptly remove any infected plants to prevent the disease from spreading.
Boxwood Mite
Boxwood mites are tiny pests that can cause significant damage to boxwoods, particularly those grown in full-sun or partial shade. These pests feed on the underside of the leaves, causing them to take on a mottled or bronzed appearance.
Severe infestations can lead to premature leaf drop and stunted new growth. Regular monitoring and the use of horticultural oils can help manage boxwood mite populations.
Root Rot
Root rot is a common issue for boxwoods, especially when they are planted in poorly drained soils or in areas that receive excessive water. The disease is caused by various fungi and leads to the decay of the root system.
Symptoms include wilting, yellowing, or browning of the leaves, and in advanced cases, the entire plant may die.
To prevent root rot, ensure your boxwoods are planted in well-drained soils and avoid overwatering, especially during the late winter and late summer months.
Common Plant Problems and Solutions for Boxwood
Brown Tips and Yellowing Leaves
One of the most common issues that affect boxwood shrubs is the browning of their tips and the yellowing of their leaves. This is often a result of full-sun exposure or poorly-drained soils.
To combat this, consider planting your boxwood in a location that offers partial shade, especially during the late summer months when the sun’s rays can be particularly harsh.
Also, ensure that the soil is well-drained to prevent waterlogging, which can lead to root rot.
Boxwood Blights
Another prevalent problem in boxwood shrubs is the occurrence of blights, such as boxwood blights and leaf spot blights. These fungal diseases can cause severe damage to the plant’s leaves and overall landscape.
To prevent these blights, it’s essential to choose disease-resistant cultivars, such as Buxus sempervirens, and to maintain good air circulation around the plants by not overcrowding them.
If blights do occur, prompt removal of the affected leaves and a fungicidal treatment can help control the spread.
Lack of New Growth
If your boxwood shrubs are not exhibiting new growth in the early spring, this may be a sign of stress or disease. This could be due to poor soil conditions or an unfavorable growing season.
To encourage new growth, ensure that the shrubs are planted in well-drained soils and receive adequate water and nutrients. Additionally, a balanced fertilizer application in late winter can help kickstart the new growth phase.
Other Guides from Planet Natural:
Sumac Tree Care: Shrub Cultivation and Support
How to Plant, Grow, and Care for Butterfly Bush (Buddleia)
Melissa Pino is a biologist, master gardener, and regular contributor for Planet Natural. Melissa’s work focuses on promoting environmentally-friendly practices, helping people create healthy gardens and finding ways to achieve overall health and wellness.
