Caryopteris, Bluebeard, Blue Mist Spirea 'Dark Knight'

Caryopteris x clandonensis

Family: Lamiaceae (lay-mee-AY-see-ee) (Info)
Genus: Caryopteris (kar-ee-OP-ter-iss) (Info)
Species: x clandonensis (klan-don-EN-sis) (Info)
Cultivar: Dark Knight



Water Requirements:

Average Water Needs; Water regularly; do not overwater

Sun Exposure:

Sun to Partial Shade



Foliage Color:

Unknown - Tell us


36-48 in. (90-120 cm)


4-6 ft. (1.2-1.8 m)


USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Where to Grow:

Unknown - Tell us


Unknown - Tell us

Bloom Color:

Medium Blue

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Bloom Size:

Unknown - Tell us

Bloom Time:

Late Summer/Early Fall

Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

From softwood cuttings

By simple layering

Seed Collecting:

Bag seedheads to capture ripening seed

Allow seedheads to dry on plants; remove and collect seeds


This plant is said to grow outdoors in the following regions:

Auburn, Alabama

Vincent, Alabama

Chino Valley, Arizona

El Mirage, Arizona

Tucson, Arizona

Knights Landing, California

Oakhurst, California

Oakland, California

Redding, California

San Jose, California

Temecula, California

Denver, Colorado

Erie, Colorado

Wheat Ridge, Colorado

Bartow, Florida

Lakeland, Florida

Nampa, Idaho

Rochester, Illinois

Bloomington, Indiana

Floyds Knobs, Indiana

Iowa City, Iowa

Hebron, Kentucky

Monroe, Louisiana

Alfred, Maine

Sandwich, Massachusetts

Dearborn Heights, Michigan

Pinconning, Michigan

Lincoln, Nebraska

Cape May, New Jersey

Millington, New Jersey

Whiting, New Jersey

Albuquerque, New Mexico

Farmington, New Mexico

Poughkeepsie, New York

Cary, North Carolina

High Point, North Carolina

Hillsborough, North Carolina

Williamsburg, Ohio(2 reports)

Chiloquin, Oregon

Portland, Oregon

Doylestown, Pennsylvania

Havertown, Pennsylvania

Philadelphia, Pennsylvania

Trafford, Pennsylvania

Barrington, Rhode Island

Simpsonville, South Carolina

Austin, Texas

Bryan, Texas

Canyon Lake, Texas

Fort Worth, Texas

Killeen, Texas

Lewisville, Texas

San Benito, Texas

Farmington, Utah

Kaysville, Utah

Magna, Utah

Sandy, Utah

South Jordan, Utah

Leesburg, Virginia

Portsmouth, Virginia

Ruckersville, Virginia

Cathan, Washington

Issaquah, Washington

John Sam Lake, Washington

North Bend, Washington

North Marysville, Washington

Priest Point, Washington

Seattle, Washington

Shaker Church, Washington

Stimson Crossing, Washington

Vancouver, Washington

Weallup Lake, Washington

Milwaukee, Wisconsin

show all

Gardeners' Notes:


On May 20, 2019, Scottypotty from Mico, TX wrote:

This is a great plant in Medina county, Mico, Texas, Lower Texas Hill Country. I have used it around the pathways in my zero scape garden in 5 tall focal accent pots with drainage holes, they tumble over the edges with their blue blooms and are fabulous! I had tried other things, but nothing could take the Texas heat, sun and no water but these; not to mention foraging deer helping themselves! They do drop their leaves in fall, but spring and an early fall re-bloom are worth it! thinking a few in the ground this spring might even be more rewarding!


On Jul 8, 2017, pammarko from Portland, OR wrote:

These plants thrive in Portland, Oregon! I have two: blue mist and dark knight. I have had them in my west-facing back yard for 8 years where they have survived Portland's rainiest years on record, as well as snow and ice. Portland's Dec 2016 and Jan/Feb of 2017 had several multi-week stretches of heavy snow and ice, and my caryopterises/caryopteri(?) didn't suffer a bit. I usually cut them back in late winter when I think about it. My blue mist grows so big that I've even had to cut it back in the middle of summer, and it rebounds with new growth and blooms until late winter. The fragrance of the leaves and blooms is intoxicating. I love this plant!


On Nov 17, 2015, coriaceous from ROSLINDALE, MA wrote:

Flower color is deeper than other cultivars like 'Longwood Blue', and the foliage is less silvery.

I cut back hard in early spring, but I first wait to see where new growth emerges, and I don't cut back further than that.

Height is about 30-36".

This is a short-lived shrub, like a buddleia.


On Sep 4, 2015, chasinsf from Oakhurst, CA wrote:

I planted my Dark Knight in late spring and it has done well in the Sierra foothills. I give it about 2-3 gallons of water every 10 days and it has thrived throughout a hot summer (about 95 degrees daily). Since we are in the middle of a severe drought, I am happy I selected this plant.


On Nov 7, 2014, virginiarose from Portsmouth, VA (Zone 8a) wrote:

Mine got big and floppy, probably because I did not hard prune it in the spring. I sure will next year, this is a nice little shrub but needs some pruning through the growing season to keep a tidy shape, that is if you can get the bees off it long enough to do that. Bees love this plant!


On Feb 3, 2014, joimack6953 from Wheat Ridge, CO wrote:

I hard prune this back late winter or early spring; about 1/3 of the plant; and it blooms beautifully every year. So many bees gather on this plant that I can hear the buzzing when I walk through the garden. It spreads from seed and grows fairly quickly.


On Sep 24, 2012, SoNJgarden wrote:

2-yr old plant was hit hard by mildew in July-August. Most leaves fell off- just now starting to make new ones. No blooms this year. Will try hard pruning eary spring 2013. South NJ area.


On Aug 26, 2011, NoLawns from Warrenville, IL wrote:

This blue mist shrub needs to be cut down in spring. (4-6 inches) If it is cut back in fall it will die. Also, some dry leaves around the base of the plant in winter will help overwintering success. This plant has grown for many years in Zone 5 (Chicago IL)


On Sep 22, 2010, xeriman from Farmington, NM wrote:

This shrub has been doing quite well in a few xeric gardens here in northwestern New Mexico (USDA zone 6B or Sunset zone 3A). It is a valuable addition to the gardens because of its late summer blue flowers. Does well in full sun with about 3 to 5 gallons of water (per plant) per week. Not sure of the cultivar. I'm assuming 'Dark Knight'.


On Sep 6, 2010, Kellysbiz from Mission Viejo, CA wrote:

I bought this gorgeous plant at a local nursery but unfrotuantely it was rootbound to the point of no saving. Once the flowerettes started going to seed they were dying. So I took it back and got another one today. Anyone familiar with Monrovia plants, they tend to be exceptionally rootbound mainly with their five gallon plants. They say their problem with them is solved but I just got this and it isn't. Anyway, I love this plant. I have a blue and white garden area (with a few other colors too that need to be moved) and blue is so hard to find for zone 9. Everyone tends to call some purple colors blue. I completely took apart the roots on this one and then soaked it. Hope it makes it. I'm in Southern California and it's supposed to do well with our heat spells here. Not as bad as T... read more


On Aug 14, 2010, jenwaterston from Havertown, PA wrote:

This plant comes into bloom (in my Philadelphia-area) garden during mid-August, when many other plants are fading. It's a beautiful blue color and makes a nice specimen plant. I find saplings of this plant all over my full-sun garden -- I've given away and discarded the babies. Seems to thrive in well-drained, full sun conditions.


On May 27, 2009, karenathurston from Philadelphia, PA wrote:

I live in Philadelphia, PA (zone 6a) and planted a 'Longwood Blue' 2 years ago. It flowered the first year but there were no flowers at all last year. The foliage is also not as dense as the majority of photographs I have come across. I have it in morning shade/ afternoon sun in a fairly dry area that I substitute water during the hotter summer months. I'm going to try fertilizing it this summer to see if that helps it improve - it's looking kind of scraggly.


On Apr 19, 2008, ILUVTX from Fort Worth, TX wrote:

Here in Zone8a this plant grows great! It is very beautiful when it blooms in the summer and fall. All our neighbors comment how pretty it is! It is very tolerant of our Texas heat, humidity, and lack of rain in the warm months and does very well over the cooler winter months. I would recommend this plant to other gardeners in a similar climate.


On Nov 17, 2006, Marilynbeth from Hebron, KY wrote:

I love Caryopteris! I love the blue color of most of the varieties and recently saw that there is a soft pink color of a new variety this year.


On Oct 17, 2006, gardenworksva from Ruckersville, VA wrote:

Planted Dark Knight Spring '06 and having problems with the stems 'laying down' as well has becoming week and splitting off. Possibly it needs harder pruning early on. ?


On Sep 15, 2006, Leehallfae from Seattle, WA wrote:

I like the True blue flowers. It is next to the Black Hollyhock and Star Gazer Lillies, and adds quite a bit of needed contrast.


On May 30, 2005, Julia_T from Northern, VA (Zone 7a) wrote:

I planted three in partial sun in zone 7a last spring. They flowered luxuriantly the same year -- put on a real show, plus the flowers have a delicious scent. The bumblebees agreed, but we didn't get any wasps. Ours have sapphire-blue flowers and soft gray-green foliage, on a mini tree-form habit. I've heard that they can spread quite a bit, so will update if that happens.


On Aug 25, 2004, digwell from Shelburne, NS (Zone 6a) wrote:

Have just purchased caryopteris Dark Knight, and put it in a bed next to Pee Gee hydrangea. The combination of the Dark Knight blue flowers against the white of the hydrangea is a lovely fresh change from the usual reds and yellows of most late summer flowers.


On May 13, 2004, MotherNature4 from Bartow, FL (Zone 9a) wrote:

I just purchased Bluebeard 'Dark Knight' yesterday. Being a native Floridian, this was the first time I've ever heard of this lovely plant, so if anyone else from Florida has any growing suggestions, I'd appreciate any and all input. MotherNature4


On Jan 3, 2003, lupinelover from Grove City, OH (Zone 6a) wrote:

Although it is supposed to be hardy to zone 4, this plant is not reliably hardy for me, possibly because of too much moisture in the winter dormant season. The flowers are welcome in the late summer and autumn, but I must replace it every 2-3 years.