Grown for their gorgeous blossoms, bluebeard plants (Caryopteris) add a much-needed splash of purplish blue to gardens from mid to late summer in Zones 4-9. The easy-care shrub carries its spectacular display through much of the fall, mixing well with cool color palettes and acting as a refreshing contrast to the hot colors of fall.
Also called blue mist spirea, this deciduous plant features long, graceful stems covered in tiny leaves. At peak bloom, those stems are loaded with blossoms that draw in butterflies, bumblebees, and other helpful pollinators.
Caryopteris × clandonensis (a.k.a., 'blue mist' bluebeard) is one of the most popular cultivars, which bears soft, silver-green foliage. However, there are many other colorful varieties to consider. Golden foliage is one of the most appealing, with bright yellow leaves that create a stunning backdrop for the bright blue flowers. Plus, when bluebeard plants aren't in bloom, the foliage adds a visual lightness to the garden.
Bluebeard Overview
Where to Plant Bluebeard
Bluebeard plants grow best in sunny locations that receive at least 6 hours of direct sunlight each day. As one of the few flowering shrubs that bloom in late summer, bluebeard plants can add colorful interest to any cottage or perennial garden. The fragrant flowers and aromatic foliage attract pollinators, so place it in butterfly gardens or along beds and borders where its beauty can be enjoyed.
Native to the mountain slopes of eastern Asia, bluebeard is an excellent choice for xeriscaping or planting in slope gardens where other plants may falter. It's a deciduous shrub in some locations but should be treated as a woody perennial and cut back in other places, depending on the winter temperatures. Bluebeard plants also look attractive in containers, and several dwarf cultivars are now available that can fit in smaller spaces.
How and When to Plant Bluebeard
The best time to plant bluebeard is during the cooler months of spring after the last frost but before the punishing heat of summer or in the fall, approximately four weeks before frosty temperatures arrive.
- Dig a hole twice the size of the root ball and deep enough that your plant can sit at the same soil level it did in its container.
- Grasping the crown of the root ball, wiggle the plant out of its container and gently tease apart the roots. Place the plant in the hole so the crown is level with the soil.
- Backfill the soil, tamping down gently to remove air pockets, and water the plant thoroughly. For best results, add a layer of potting soil around the plant.
- If you are planting multiple bluebeard plants, space them at least 2 feet apart—unless you are forming a shrub border, in which case you can plant them a little closer together.
Bluebeard Care Tips
Bluebeard plants are relatively low-maintenance, drought-tolerant shrubs that can quickly grow to a height and width of 3 to 5 feet.
Light
Bluebeard plants thrive in full sun. Some of the older varieties of bluebeard can display a fairly loose structure of branches, but full sun ensures these plants are as dense as possible. Full sun is also ideal for the most impressive flower display; the less sun the plant gets, the fewer blossoms will appear.
Soil and Water
Bluebeard plants thrive best in loose, loamy, well-drained soils and will not tolerate wet soil. If the soil stays wet, the roots of your bluebeard plants will likely rot. Moreover, if your bluebeard plants stay too wet during the winter, they are unlikely to return in the spring. Soil pH should be neutral, but the plant will grow in slightly alkaline or acidic soil.
Young bluebeard plants need regular water to establish a robust root system. Water them when the top 2 inches of the soil are dry or if the plant shows signs of dehydration (like wilting or curling leaves). Once established, bluebeard is drought tolerant.
Temperature and Humidity
The optimal climate for bluebeard plants is 65° to 85° F with moderate humidity, but they are tolerant of high temperatures and summer humidity. If temperatures stay above 90 degrees Fahrenheit, however, they may need supplemental watering.
Bluebeard can withstand freezing temperatures, but in cooler climates, the above-ground growth may die back in the winter. This is not a cause for concern. As long as the roots remain strong, your bluebeard plants will return in the spring.
Fertilizer
Bluebeard plants do not require much fertilizer—if any. In fact, overfertilization may cause the plant to focus on foliage growth instead of producing blooms. Instead, incorporate some organic matter or compost into the planting hole before placing your bluebeard plant. This will ensure lush growth and improve soil drainage,
Pruning
You do not need to deadhead your spent bluebeard blooms to encourage continuous blooms. In fact, the dry, segmented seed pods that remain provide visual interest after the flowers are gone.
You may be tempted to prune your bluebeard plants back in the fall, but doing so could stimulate new growth that will be damaged when winter temperatures arrive. Instead, allow your bluebeard plants to die off over the winter and then prune them to approximately 6 to 8 inches from the ground in the spring. This will signal to the plant that it is time to create new growth.
Potting and Repotting
Bluebeard works beautifully in containers and makes a lovely addition to sunny patios or decks, but container-grown plants may need more care than those grown in the ground.
- Choose a container with excellent drainage large enough to accommodate the mature size of the cultivar you selected.
- Fill the container with a rich potting mix (with a neutral pH) and incorporate some organic compost. This will help aerate the soil so it accepts and stores water more efficiently.
- Make a space in the potting mix larger than the plant’s root ball and add the plant to the container so the crown of the roots sits at the same level as it did in its old pot. Fill in the space with a potting mix and water the plant thoroughly.
- Plan to water your container-grown bluebeard plant whenever the top 1 to 2 inches of soil feel dry. Feed your plant with a water-soluble fertilizer every few weeks, beginning in the spring and continuing throughout the growing season.
- When winter comes, reduce watering and consider moving your potted bluebeard plant into an unheated, protected area (like a garage or shed) where it will be safe from the elements. You can move it back outside after the danger of frost has passed.
Bluebeard plants tolerate transplantation, so if you need to move yours to a larger container, the best time is in early spring or the cooler (but not cold) fall months.
Pests and Problems
Bluebeard has few problems with pests and diseases, but root and crown rot can be an issue if the plant’s soil is too wet.
In some areas, four-lined plant bugs can cause trouble for bluebeard plants, leaving behind dark, round spots often mistaken for leaf spots. Treatment is usually not necessary as the life cycle of four-lined plant bugs only allows one generation per year. Removal is nearly impossible as they are notoriously timid, but if spotted early, you can treat your plants with insecticidal soap to eliminate the nymphs.
How to Propagate Bluebeard
The easiest way to propagate bluebeard plants is through stem cuttings, but you can also collect the seed pods in the fall and store them in a plastic bag filled with damp sphagnum moss or press the freshly harvested seeds into a damp seed-starting mix kept at 68° F until germination.
Stem cuttings are a more reliable propagation method—especially since most bluebeard cultivars found in nurseries are hybrids.
- Take a soft-wood cutting in late spring. Using sharp garden shears, remove a 6-inch section from a new growth stem.
- Remove any leaves from the lower part of the cutting and dip the cut end in rooting hormone.
- Stick the cutting (cut end down) into a pot filled with good quality potting mix and keep it in an area with bright indirect light until it takes root.
- Once a strong root system is developed, it can be transplanted outside.
Types of Bluebeard
Many of the new bluebeard varieties are dwarf in size, making them good choices for smaller spaces and containers. Other new varieties display colored foliage that won't burn in the sun. New and improved varieties boast bigger and bluer blooms.
'Beyond Midnight' Bluebeard
Caryopteris x clandonensis 'Beyond Midnight' is a recent introduction that has deep, dark green foliage with a lovely gloss. They are compact with deep blue flowers. Zones 5-9
'Blue Mist' Bluebeard
Caryopteris 'Blue Mist' is one of the most commonly seen cultivars of bluebeard. It grows 3 feet tall and features light blue flowers with an open, loose growth habit perfect for cottage gardens. Zones 5-8
'Longwood Blue' Bluebeard
Caryopteris 'Longwood Blue' is one of the most outstanding introductions. It features sky-blue flowers that appear in midsummer and last until fall. It grows 4 feet tall. Zones 5-8
Petit Bleu Bluebeard
Caryopteris 'MinBleu' is a French introduction that flaunts rich sky-blue flowers on a compact, 3-foot-tall plant. Zones 5-8
Sunshine Blue Bluebeard
Caryopteris incana 'Jason' offers large gold leaves that are a stellar complement to the rich blue flowers. It grows 4 feet tall and wide. Zones 5-9
Companion Plants for Bluebeard
Coreopsis
The sunny yellow, red, orange, or pink blossoms of coreopsis look pretty alongside the true blue blooms of the bluebeard shrub. Coreopsis is more low-growing than bluebeard but also thrives in lots of sunlight and well-draining soil. Zones 3-9
Lantana
If you are looking for a plant that can survive the hot, dry spots of your garden while also attracting pollinators, lantana is a great option. It produces orange, pink, purple, red, yellow, or white blooms in summer and fall and (like bluebeard) prefers full sun and well-draining soil. Zones 9-11
Lantana is considered invasive in some states. Check your local extension service before adding it to your garden.
Zinnia
Like bluebeard, zinnias prefer full sun and are drought-tolerant once established. They are a favorite with pollinators such as hummingbirds, bees, and butterflies and come in many shapes, sizes, and colors (except blue). Zinnias are some of the toughest annuals you can put in your garden. Zone 2-11
Garden Plans for Bluebeard
Property Line Garden Plan
'Dark Knight' bluebeard (Caryopteris x clandonensis) edges this property line garden plan and provides a stunning contrast to the bright yellow witch hazel planted nearby. Situate this garden plan along the edge of your landscape to provide a pretty barrier between your yard and a neighbor’s —or plant it along a fence or wall to soften the space.
Frequently Asked Questions
- Why does my bluebeard plant look like it didn’t survive the winter?The top growth of bluebeard is not nearly as winter-hardy as the roots. But bluebeard blooms on new growth, so this characteristic typically isn't a problem. If you think you have lost your plants to winter, wait and watch for signs of growth at the base. For the most vigorous and compact growth, cut back the shrub each spring. Pruning encourages growth from the base and prevents plants from dying out in the middle.
The top growth of bluebeard is not nearly as winter-hardy as the roots. But bluebeard blooms on new growth, so this characteristic typically isn't a problem. If you think you have lost your plants to winter, wait and watch for signs of growth at the base. For the most vigorous and compact growth, cut back the shrub each spring. Pruning encourages growth from the base and prevents plants from dying out in the middle.
- Is bluebeard considered invasive?Bluebeard is not classified as invasive in any state, but it can self-seed freely if not monitored. You can minimize the risk of unwanted plants by removing the blooms before they go to seed or by pulling up any volunteer plants as they emerge.
Bluebeard is not classified as invasive in any state, but it can self-seed freely if not monitored. You can minimize the risk of unwanted plants by removing the blooms before they go to seed or by pulling up any volunteer plants as they emerge.