Brown-eyed Susan

Questions about brown-eyed Susan

Does brown-eyed Susan need sun or shade?

Brown-eyed Susan grows in full sun (6 or more hours of direct sun a day) and part sun (4 to 6 hours of sun, including some afternoon sun).

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

What zones does brown-eyed Susan grow in?

USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).

Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.

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

When does brown-eyed Susan flower in my zone?

In zone 5 it flowers late 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 brown-eyed Susan 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 4 ft (120 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.

How many brown-eyed Susan 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 three in one group.

Is brown-eyed Susan 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.

Do deer eat brown-eyed Susan?

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

Will brown-eyed Susan spread?

It seeds itself about; the risk of it taking over is moderate. Short-lived, but keeps going by self-seeding. Thin or move seedlings where they are not wanted.

What flowers after brown-eyed Susan?

Brown-eyed Susan is over by early October. These start as it finishes and carry the same spot on, so it never goes flat:

• Chrysanthemum 'Sheffield Pink': from late September to early November, 2½ ft tall, to stand in front of it and cover its fading stems.
• Tatarian aster 'Jindai': from early October to early November, 4 ft tall.
• Japanese onion 'Ozawa': from early October to early November, 10 in tall, to stand in front of it and cover its fading stems.

What does brown-eyed Susan look like in winter?

Brown-eyed Susan 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 brown-eyed Susan good for bees and butterflies?

Brown-eyed Susan is visited by pollinators, butterflies and songbirds.

It is a host plant: the caterpillars of silvery checkerspot and wavy-lined emerald 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.