Information About Blue Lace Flower

Information About Blue Lace Flower

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Blue Lace Flower Info: Tips For Growing Blue Lace Flowers

By Mary H. Dyer, Credentialed Garden Writer

The blue lace flower is an eye-catching plant that displays rounded globes of tiny, star-shaped flowers in shades of sky-blue or purple. Such a beautiful plant deserves a place in the garden. Read here to learn more about growing blue lace flowers.

Bloomstruck Hydrangea Plant Profile

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Bloomstruck hydrangea belongs to the "bigleaf" category of hydrangea bushes. It is in this hydrangea category that the color of the flowers is famously determined by the pH level of the soil. Bloomstruck hydrangea is also part of the Endless Summer series. This series is popular because it has been touted as the "reblooming hydrangea." Bloomstruck hydrangea produces large (3.5 to 5 inches across), mophead-style flower heads. Also attractive are its reddish-purple branches and dark-green leaves.

Botanical Name Hydrangea macrophylla 'P11HM-11'
Common Names Bloomstruck hydrangea
Plant Type Deciduous shrub
Mature Size 3 to 4 feet high and 4 to 5 feet wide
Sun Exposure Prefers partial shade generally but can tolerate some sun under certain conditions
Soil Type Fertile, well-drained
Soil pH Below 5.5 for blue flowers, 5.5 to 6.5 for purple flowers, above 6.5 for reddish flowers
Bloom Time July and August
Flower Color Varies from reddish to violet-blue depending on the soil pH
Hardiness Zones 4 to 9
Native Area Hydrangea macrophylla is native both to Asia and to parts of the New World

Trachymene Growing and Care Guide

Common Names: Lace Flower, Wild Parsnip, Rottnest Island Daisy, Blue Lace Flower, Spongefruit, Native Candytuft.
Family: Araliaceae.
Life Cycle: Half hardy perennial commonly grown as a half hardy annual by gardeners.
Height: 8 to 20 inches (20 to 50 cm).
Native: Australasia.
Growing Region: Zones 3 to 8. As a perennial in zones 8 to 10.
Flowers: Summer and/or autumn.
Flower Details: Purple, lavender, white. Tiny flowers in mass.
Foliage: Light green. Obtuse. Obcordate. Divided. Sticky.
Sow Outside: Cover seed. Following the last frost. Spacing 8 to 12 inches (20 to 30 cm).
Sow Inside: Use peat pots. Germination time: two weeks to one month in the dark. Temperature 70°F (21°C). Two months before expected last frost. Transplant outdoors following the last frost.
Requirements: Full sunlight. Ordinary soil. Organic soil. Moist soil. Can survive in dry soils. Provide support. Occasional watering during prolonged dry periods. Pinch tips.

Trachelium Species, Blue Lace Flower, Blue Throatwort

Family: Campanulaceae (kam-pan-yew-LAY-see-ee) (Info)
Genus: Trachelium (trak-ELL-ee-um) (Info)
Species: caeruleum (see-ROO-lee-um) (Info)
Synonym:Trachelium azureum
Synonym:Trachelium caeruleum f. brevidentatum
Synonym:Trachelium caeruleum f. isabellinum
Synonym:Trachelium caeruleum f. longiflorum


Water Requirements:

Drought-tolerant suitable for xeriscaping

Sun Exposure:


Foliage Color:




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)

USDA Zone 10a: to -1.1 °C (30 °F)

USDA Zone 10b: to 1.7 °C (35 °F)

USDA Zone 11: above 4.5 °C (40 °F)

Where to Grow:

Grow outdoors year-round in hardiness zone

Can be grown as an annual


Handling plant may cause skin irritation or allergic reaction

Bloom Color:

Bloom Characteristics:

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

Bloom Size:

Bloom Time:

Other details:

Soil pH requirements:

Patent Information:

Propagation Methods:

From seed sow indoors before last frost

From seed direct sow after last frost

Seed Collecting:

Allow pods to dry on plant break open to collect seeds

Properly cleaned, seed can be successfully stored


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

La Canada Flintridge, California

Gardeners' Notes:

On Apr 26, 2011, kaydiehl from Pasadena, CA wrote:

Looks lovely in among the roses. Blue softens the contrast among bright roses that might otherwise clash. Gets tall enough to need support. I grow them through short hoops about a foot tall so I don't have to stake each individual cane. Once the roses are up and the tracheliums are well sprouted, the supports are invisible.

On May 16, 2006, gardenbeads from Warren, MI (Zone 5a) wrote:

This plant is commonly called Blue Lace flower or Blue Throatwart. It is a tender perennial and does not overwinter in Michigan but can be grown as an annual. It will grow to about 2 1/2 feet high and has a bush-like habit. It flowers continuously from summer to fall and does best in sun/part shade. A great cut flower, one of my favorites.

On Nov 22, 2002, jkom51 from Oakland, CA (Zone 9b) wrote:

Beautiful flower heads on slender stems plant needs some staking when it gets to full 3' height. Flowerheads are fragrant, very similar to lilac with a vanilla scent. Excellent as cut flowers.