Illustration
Hollyhock 'Blacknight'
Alcea rosea 'Blacknight'
Hollyhock 'Blacknight' blooms from June through September.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Hollyhock 'Blacknight'
Plant it in full sun. It prefers moderate water. It is hardy in USDA zones 2–11. Expect it to reach about 5 ft tall and 2 ft wide at maturity, in roughly 2 years (not yet checked).
What this means
Generated by an earlier AI feature of BloomsEye and not yet checked against outside sources, its scientific name included, so treat every fact above as a starting point. An audit keeps its values consistent with the rest of the library, which is not the same as being right. The source-by-source check is working through the whole library in the open, and a checked plant says so in this row.
When to plant Hollyhock 'Blacknight'
Plant Hollyhock 'Blacknight' in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 6, the middle of its hardy zones 2 to 11, spring means March to May and fall means August or September. Once settled, it blooms from June to September.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 6, the middle of this plant's hardy range, start with zone 6 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Hollyhock 'Blacknight' get?
5 fttall5 ft 7 inan adult2 ftwideSee Hollyhock 'Blacknight' in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Hollyhock 'Blacknight'
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Hollyhock 'Blacknight' about 2 ft apart, center to center, so each plant has room to reach its full width.
Add Hollyhock 'Blacknight' to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Good to know about Hollyhock 'Blacknight'
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note.
Safety
Handling the foliage can cause skin irritation or contact dermatitis in some people, and mild stomach upset in animals that eat it. Wear gloves. per Cornell
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.