Butterfly bush 'Black Knight'

Questions about butterfly bush 'Black Knight'

Does butterfly bush 'Black Knight' need sun or shade?

Butterfly bush 'Black Knight' grows in full sun (6 or more hours of direct sun a day).

It wants ordinary well-drained soil, of average fertility, and little watering once settled. Once settled in, it stands drought.

What zones does butterfly bush 'Black Knight' grow in?

USDA zones 5 to 9. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).

Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.

When does butterfly bush 'Black Knight' flower in my zone?

In zone 5 it flowers early July to early October. As a summer flower it moves about half a week for every zone: earlier where it is warmer.

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 butterfly bush 'Black Knight' be planted?

5 ft (150 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 6½ ft (200 cm), so a group knits into one patch.

It grows 8 ft (250 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many butterfly bush 'Black Knight' plants do I need?

Usually one. At 5 ft (150 cm) across, it is a plant you place, not one you mass. For a hedge or screen, set them 5 ft apart: three plants for a 10 ft run.

Is butterfly bush 'Black Knight' poisonous to dogs and cats?

No toxicity is recorded for dogs, cats, horses or people, according to NC State Extension.

"Not toxic" is not "edible": a pet that eats a lot of any plant can be sick.

What can I plant instead of butterfly bush 'Black Knight'?

Butterfly bush 'Black Knight' is listed as invasive in parts of North America (1 listing), so the planner never uses it. These do the most similar job:

• Rose of Sharon: the same job in a bed, the same flowering time and the same colour; 20 in taller.
• Bodinier's beautyberry 'Profusion': the same job in a bed; 12 in wider, flowers mid July to early August.
• Butterfly bush 'Miss Molly': the same job in a bed and the same flowering time; 3½ ft shorter, 12 in narrower.

Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.

Do deer eat butterfly bush 'Black Knight'?

Mostly not. NC State lists it as resistant to deer and rabbits. No plant is proof against a hungry deer in a hard winter, but this one is low on the menu.

Will butterfly bush 'Black Knight' spread?

It seeds itself about; the risk of it taking over is high. Self-seeds freely on wind-blown seed and is invasive along rivers and on disturbed ground. Listed as a noxious weed in Oregon and Washington. Remove every spent flower spike, or plant a sterile variety.

It is listed as invasive in parts of North America, and the planner never chooses it.

What flowers after butterfly bush 'Black Knight'?

Butterfly bush 'Black Knight' is over by early October. These start as it finishes and carry the same spot on, so it never goes flat:

• Swamp sunflower: from late September to late October, 6½ ft tall.
• Tatarian aster 'Jindai': from early October to early November, 4 ft tall, to stand in front of it and cover its fading stems.
• Bodnant viburnum 'Dawn': from early November to late December, 10 ft tall.

What does butterfly bush 'Black Knight' look like in winter?

Butterfly bush 'Black Knight' drops its leaves and stands as bare branches. That is when to see its shape, and to prune it if it needs pruning.

Is butterfly bush 'Black Knight' good for bees and butterflies?

Butterfly bush 'Black Knight' is visited by pollinators, butterflies and hummingbirds.