Create Your Garden

Alcea rosea ‘Blacknight’ (Hollyhock)

Hollyhock 'Blacknight', Spotlight Series

Alcea rosea 'Blacknight',Hollyhock 'Blacknight', Tall Perennial, Black flowers, Black Alcea, Black Hollylock
Alcea rosea 'Blacknight',Hollyhock 'Blacknight', Tall Perennial, Black flowers, Black Alcea, Black Hollylock
Alcea rosea 'Blacknight',Hollyhock 'Blacknight', Tall Perennial, Black flowers, Black Alcea, Black Hollylock

Providing architectural height to borders, Alcea rosea ‘Blacknight’ (Hollyhock) is a robust perennial that produces tall, sturdy spikes of funnel-shaped, deep black-purple, single flowers, 4 in. across (10 cm), with a bright buttery-yellow throat. Blooming from mid to late summer, the striking flowers are arranged all around the spike and bloom from the bottom up. An old garden favorite, Hollyhock is best when grown against a wall or fence or at the back of the border.

Alcea rosea ‘Blacknight’ belongs to the Spotlight Series, noted for its truly perennial cultivars, not biennial.

Size: Grows vigorously up to 5-6 ft. high (150-180 cm) and 2 ft. wide (60 cm). Hollyhocks easily self-seed and can establish colonies in the garden.

Uses: Given its stature, it’s excellent as a background plant in perennial borders. It also suits cottage gardens and can be used as a natural screen or backdrop against fences and walls.

Pollinators: Hollyhocks attract various pollinators, especially bees, butterflies, and hummingbirds, which are drawn to their large, nectar-rich flowers.

Toxicity: Hollyhocks are generally considered non-toxic to humans, but like many plants, they can cause allergic reactions in sensitive individuals.

Deer and Rabbit: Hollyhocks are usually not the first choice for deer and rabbits; however, when food sources are scarce, they might nibble on them.

Invasiveness: Alcea rosea is native to Europe and Asia. It may become weedy and potentially invasive in some areas.

Hollyhock Growing Tips

Location: Hollyhocks prefer full sun but can tolerate light shade. They need at least 6 hours of direct sunlight for best flower production. Pick a site sheltered from the wind to prevent these tall plants from flopping.

Soil: Hollyhocks tolerate a wide range of soil conditions but will not tolerate wet winter soils. Plant in well-draining, fertile soils for optimal results.

Watering: Young plants thrive in moist environments. Mature hollyhocks typically require water during extended periods of heat and dryness.

Pruning: After flowering, cut back the stalks to encourage a second bloom. At the end of the season, remove old stalks to reduce disease risk.

Propagation: Hollyhocks can be propagated from seeds. Sow seeds outdoors anytime from spring (after all danger of frost has passed.) until 2 months before the first heavy fall frost. If you prefer to start them indoors, do so about 6-8 weeks before the last expected frost date in your area.

Pest and diseases: Hollyhocks are susceptible to several pests and diseases, including anthracnose, leaf spot, rust, Japanese beetles, and spider mites.

Hollyhock: How to Grow and Care with Success


Hollyhocks, while undeniably beautiful, can be finicky to cultivate. Our well-researched guide provides insights into ensuring thriving growth, achieving the most vibrant blooms, and prolonging their lifespan, allowing gardeners to fully enjoy the majestic allure of hollyhocks in their landscape.

Requirements

Hardiness 3 - 9
Heat Zones 3 - 10
Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Perennials
Plant Family Malvaceae
Genus Alcea
Common names Hollyhock
Exposure Full Sun
Season of Interest Summer (Mid, Late),
Height 5' - 6' (150cm - 180cm)
Spread 1' - 2' (30cm - 60cm)
Spacing 24" (60cm)
Maintenance Low
Water Needs Average
Soil Type Chalk, Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Well-Drained
Characteristics Cut Flowers, Showy
Tolerance Rabbit, Deer
Attracts Butterflies, Hummingbirds, Bees
Garden Uses Beds And Borders, Wall-Side Borders, Walls And Fences
Garden Styles Coastal Garden, Informal and Cottage
How Many Plants
Do I Need?
Guides with
Alcea (Hollyhock)
Not sure which Alcea (Hollyhock) to pick?
Compare Now

Alternative Plants to Consider

Alcea rosea ‘Chater’s Double Chamois’ (Hollyhock)
Alcea rosea ‘Chater’s Double Salmon Pink’ (Hollyhock)
Alcea rosea ‘Chater’s Double Rose’ (Hollyhock)
Alcea rosea ‘Chater’s Double Maroon’ (Hollyhock)
Alcea rosea ‘Chater’s Double White’ (Hollyhock)
Alcea rosea ‘Chater’s Double Red’ (Hollyhock)

Recommended Companion Plants

Hibiscus ‘Ballet Slippers’ (Rose Mallow)
Coreopsis ‘Starlight’ (Li’l Bang Series)
Eryngium planum ‘Blue Glitter’ (Flat Sea Holly)

Find In One of Our Guides or Gardens

How to Create an Enchanting Butterfly Garden
For the Love of Butterflies: Best Flowers to Attract them to Your Garden
6 Reasons You Should Create a Butterfly Garden
For the Love of Bees: Best Flowers to Attract them to Your Garden
Hollyhock: How to Grow and Care with Success
Alcea (Hollyhock)
Native Plant Alternatives to Alcea rosea (Hollyhock)
Best Flowers to Attract Hummingbirds
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
Buy Plants

Requirements

Hardiness 3 - 9
Heat Zones 3 - 10
Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Perennials
Plant Family Malvaceae
Genus Alcea
Common names Hollyhock
Exposure Full Sun
Season of Interest Summer (Mid, Late),
Height 5' - 6' (150cm - 180cm)
Spread 1' - 2' (30cm - 60cm)
Spacing 24" (60cm)
Maintenance Low
Water Needs Average
Soil Type Chalk, Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Well-Drained
Characteristics Cut Flowers, Showy
Tolerance Rabbit, Deer
Attracts Butterflies, Hummingbirds, Bees
Garden Uses Beds And Borders, Wall-Side Borders, Walls And Fences
Garden Styles Coastal Garden, Informal and Cottage
How Many Plants
Do I Need?
Guides with
Alcea (Hollyhock)
Not sure which Alcea (Hollyhock) to pick?
Compare Now

Gardening Ideas

Plant Calculator

How many Alcea rosea ‘Blacknight’ (Hollyhock) do I need for my garden?

Input your garden space dimensions

Your Shopping List

Plant Quantity
Alcea rosea ‘Blacknight’ (Hollyhock) N/A Buy Plants

Please Login to Proceed

You Have Reached The Free Limit, Please Subscribe to Proceed

Subscribe to Gardenia

To create additional collections, you must be a paid member of Gardenia
  • Add as many plants as you wish
  • Create and save up to 25 garden collections
Become a Member

Plant Added Successfully

You have Reached Your Limit

To add more plants, you must be a paid member of our site Become a Member

Update Your Credit
Card Information

Cancel

Create a New Collection

Sign Up to Our Newsletter

    You have been subscribed successfully

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Find your Hardiness Zone

    Find your Heat Zone

    Find your Climate Zone