Butterfly weed

Questions about butterfly weed

Does butterfly weed need sun or shade?

Butterfly weed grows in full sun (6 or more hours of direct sun a day).

It wants dry, sharply drained soil, on the lean side, with no feeding, and little watering once settled. Once settled in, it stands drought.

What zones does butterfly weed 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 butterfly weed flower in my zone?

In zone 5 it flowers late June to early August. 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 weed be planted?

18 in (45 cm) apart, from the middle of one plant to the middle of the next. That is about its full width, so each plant keeps its own outline.

It grows 24 in (60 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many butterfly weed 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 a group of three or five, with a second group further along in the other number.

In the bed above, the planner used four in one group.

Is butterfly weed poisonous to dogs and cats?

Yes: moderate toxicity to people, dogs, cats and horses. All parts are poisonous if eaten. The sap can irritate skin and eyes.

Rated from NC State Extension and the ASPCA. Where references disagree, the more cautious rating is used.

Is there a pet-safe plant like butterfly weed?

These come closest to doing what butterfly weed does, and no toxicity is recorded for them:

• Coneflower 'Cheyenne Spirit': the same job in a bed, the same size and the same colour; flowers late June to early September, wants average soil.
• Common blanket flower: the same job in a bed and the same size; flowers mid June to early September, yellow, not orange.
• Sunset hyssop: the same job in a bed, the same size and the same colour; flowers mid July to mid September, fine leaves, not medium.

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 weed?

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.

What flowers after butterfly weed?

Butterfly weed is over by early August. These start as it finishes and carry the same spot on, so it never goes flat:

• Lilyturf: from early August to mid September, 16 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.
• Little bluestem 'Standing Ovation': from early August to mid September, 3½ ft tall.

What does butterfly weed look like in winter?

Butterfly weed dies down to the ground and there is nothing to see until spring. The old stems can be cut in autumn, or left until spring as shelter for overwintering insects.

Is butterfly weed good for bees and butterflies?

Butterfly weed is visited by pollinators, bees, specialist bees, butterflies, moths and hummingbirds.

It is a host plant: the caterpillars of monarch (at risk), queen, gray hairstreak and milkweed tussock moth feed on its leaves. A butterfly can only lay its eggs on its host plants, so these do more for it than any nectar flower.

It is native to the United States and Canada.