Black hollyhock
Alcea rosea 'Nigra' · Malvaceae
Tall spires of single, satiny flowers in the darkest maroon, close to black, each with a yellow throat. Grown in cottage gardens since the 1600s.
- Size
- 6 ft tall, 24 in wide
- Zones
- 3 to 9
- Light
- Full sun
- Flowers
- Late June to late August
- Pets
- No toxicity recorded
- Job in a bed
- Accent
A bed built around black hollyhock
The planner designed this bed around black hollyhock when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden in zone 6, full sun. It chose the other plants from the 966 that suit those conditions, and says below why black hollyhock stands where it does.
The plants
- 1 Black hollyhock × 3, purple
- 2 Winter heath × 11, pink
- 3 Sea thrift × 8, white
- 4 Sneezeweed 'Sahin's Early Flowerer' × 3, orange
- 5 Silver sage × 1, silver leaves
- 6 Italian bugloss 'Dropmore' × 3, blue
- 7 Darwin hybrid tulip × 7, red
- 8 Ornamental onion 'Purple Sensation' × 5, purple
Why this plant
- The only spires. The others are bells, globes, daisies and others. Shape reads at a distance, where colours blur.
Why here
- Anchors a back corner. At 6 ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to sneezeweed 'Sahin's Early Flowerer' (3 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- 3 plants in one clump. A single spire is too slight to hold a place alone, so here the accent is a clump.
Why now
- In flower for 9 weeks. From late June to late August.
- Part of the bed's peak. With sneezeweed 'Sahin's Early Flowerer' and Italian bugloss 'Dropmore' in late June: 3 kinds at once. No week has more.
Planned as a cottage garden: 29 of the 29 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. The flowering year starts with winter heath in late January and ends with sneezeweed 'Sahin's Early Flowerer' in early October. Cool colours (purple, pink and blue) with orange and red as the warm notes, and white to calm things between them.
The planner's own design check: 10 Excellent, 6 Good, 1 Satisfactory. It flags one thing to watch: Nothing on this plan is highly poisonous or an aggressive spreader.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where black hollyhock goes in a border
At 6 ft it belongs at the back of a bed. In the planner's ten height classes it is very tall (5 to 6½ ft).
Its job: accent. An upright plant used singly, like a punctuation mark, and repeated at intervals to give the bed rhythm.
Plant it against a pale wall or behind silver leaves, where the dark flowers show. It is short-lived but seeds itself, and the seedlings come true if no other hollyhock grows nearby.
- Against walls and fences
- Cottage gardens
- Dark accents among pastels
What to plant with black hollyhock
Plants recorded as good partners for it, and what each pairing does:
- Lamb's ear: its silver leaves are a setting for the flowers, before and after; a low mound at the foot of its spires; low enough (12 in) to stand in front of it.
- Catmint 'Six Hills Giant': in flower together for nine weeks, from late June; fine leaves against its bold ones; a low mound at the foot of its spires.
- Shasta daisy 'Becky': in flower together for eight weeks, from early July; medium leaves against its bold ones; low enough (3½ ft) to stand in front of it.
Questions about black hollyhock
Does black hollyhock need sun or shade?
Black hollyhock grows in full sun (6 or more hours of direct sun a day).
It wants ordinary well-drained soil, rich in organic matter, and a good soak in dry spells.
What zones does black hollyhock grow in?
USDA zones 3 to 9. It is hardy to zone 3, which means it survives winter nights down to about −30 °F (−34 °C).
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does black hollyhock flower in my zone?
In zone 5 it flowers late June to late August. As a summer flower it moves about half a week for every zone: earlier where it is warmer.
| Zone 3 | Early July to late August |
|---|---|
| Zone 4 | Early July to late August |
| Zone 5 | Late June to late August |
| Zone 6 | Late June to late August |
| Zone 7 | Late June to mid August |
| Zone 8 | Late June to mid August |
| Zone 9 | Mid June to early August |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should black hollyhock be planted?
18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 24 in (60 cm), so a group knits into one patch.
It grows 6 ft (180 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many black hollyhock plants do I need?
At 18 in apart, set out in staggered rows:
- 5 to fill 10 square feet (about 1 m²)
- 7 for a single row 10 ft (3 m) long
- 17 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, repeated along the bed at intervals; a slender one reads better as a clump of three.
In the bed above, the planner used three in one group.
Is black hollyhock poisonous to dogs and cats?
No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension and the ASPCA.
"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.
Is there a native plant like black hollyhock?
Black hollyhock comes from Turkey and western Asia. These North American natives come closest to doing its job:
- Tall larkspur: the same job in a bed and the same flowering time; 12 in shorter, blue, not purple.
- Prairie blazing star: the same job in a bed and the same colour; 24 in shorter, flowers mid July to late August.
- Rattlesnake master: the same job in a bed and the same flowering time; 24 in shorter, white, not purple.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Do deer eat black hollyhock?
Mostly not. NC State lists it as resistant to rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.
Will black hollyhock spread?
It seeds itself about; the risk of it taking over is moderate. Short-lived, but self-seeds freely around the parent plant. Pull unwanted seedlings while small.
What flowers after black hollyhock?
Black hollyhock is over by late August. These start as it finishes and carry the same spot on, so it never goes flat:
- Garden chrysanthemum: from mid September to late October, 24 in tall, to stand in front of it and cover its fading stems.
- Sedum 'Autumn Joy': from mid August to mid October, 24 in tall, to stand in front of it and cover its fading stems.
- Blue sage: from late August to mid October, 4 ft tall, to stand in front of it and cover its fading stems.
What does black hollyhock look like in winter?
Black hollyhock dies down, but leave the stems standing: the seed heads stand through the winter, and songbirds eat the seed. Cut them down in early spring, before the new shoots come.
Is black hollyhock good for bees and butterflies?
Black hollyhock is visited by pollinators, bees, butterflies, hummingbirds and songbirds.
More Alcea
- Hollyhock Alcea rosea
- Russian hollyhock Alcea rugosa
In these guides
- Plants that grow near black walnut
- Rabbit-resistant plants
- Pet-safe plants for a sunny border
- Plants for hummingbirds
- Plants for butterflies
- Plants for bees
- Plants that feed garden birds
- Tall perennials and grasses for the back of a border
- Plants with spires: vertical accents
Zone guides: Zone 3 · Zone 4 · Zone 5 · Zone 6 · Zone 7 · Zone 8 · Zone 9
Every fact on record
- Type
- Perennial
- Size
- 6 ft (180 cm) tall, 24 in (60 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Very tall (5 to 6½ ft)
- Place in the bed
- Back
- Flowers
- Late June to late August; upright spires; purple, red
- Leaves
- Bold texture, herbaceous; green
- Shape
- Upright, self-seeding
- Hardy in
- USDA zones 3 to 9
- Light
- Full sun
- Soil
- Rich, well-drained
- Water
- Moderate
- Feeding
- Moderate, in spring
- Family
- Malvaceae
- Comes from
- Turkey and western Asia
- Attracts
- Pollinators, bees, butterflies, hummingbirds, songbirds
- Stands up to
- Rabbits, black walnut
Checked against NC State Extension, ASPCA poison lists and VASCAN (plants of Canada). Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.