PlantFiles: Blue Mist Spiraea, Bluebeard Caryopteris x clandonensis 'Dark Knight'
It's time to read and vote for your favorite article in the 2013 Write-Off Contest! The four finalist's articles are featured in the May 13 newsletter and can be found through this link. Hurry! Voting ends May 18.
Hardiness: 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)
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 Texas but hot for us in the 90's. Plus I'm on the hunt for summer blooming plants for this zone. My garden looks baren from mid-summer to February, yuk. Anyone know any other blue plants that grow here?
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 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.
This plant has been said to grow in the following regions:
Auburn, Alabama Chino Valley, Arizona El Mirage, Arizona Tucson, Arizona Knights Landing, California Oakland, California Temecula, California Edgewater, Colorado Erie, 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 Cedar Glen Lakes, New Jersey Millington, New Jersey Albuquerque, New Mexico Ojo Amarillo, New Mexico Red Oaks Mill, New York High Point, North Carolina Mountain View, North Carolina Williamsburg, Ohio (2 reports) Chiloquin, Oregon Doylestown, Pennsylvania Havertown, Pennsylvania Philadelphia, Pennsylvania Trafford, Pennsylvania Barrington, Rhode Island Austin, Texas Canyon Lake, Texas Copper Canyon, Texas Killeen, Texas Richland Hills, Texas Alta, Utah Farmington, Utah Fruit Heights, Utah Leesburg, Virginia Ruckersville, Virginia Cathan, Washington Issaquah, Washington North Bend, Washington Seattle, Washington Vancouver, Washington Madison, Wisconsin Milwaukee, Wisconsin