Sundrops
Oenothera fruticosa · Onagraceae
Clear, bright yellow cups open from red buds in early summer. The evergreen rosettes of leaves turn red in winter.
- Size
- 18 in tall, 18 in wide
- Zones
- 4 to 8
- Light
- Full sun to part sun
- Flowers
- Late May to mid July
- Pets
- No toxicity recorded
- Job in a bed
- Drift
A bed built around sundrops
The planner designed this bed around sundrops when this page was made: a 12 × 6 ft (3.7 × 1.8 m) naturalistic planting in zone 6, full sun. It chose the other plants from the 715 that suit those conditions and its dry soil, and says below why sundrops stands where it does.
The plants
- 1 Sundrops × 3, yellow
- 2 Heath aster 'Snow Flurry' × 11, white
- 3 Sea thrift × 3, pink
- 4 Little bluestem 'Standing Ovation' × 3, tan
- 5 Wallflower 'Bowles's Mauve' × 3, purple
- 6 Silver sage × 1, silver leaves
- 7 Allium 'Ambassador' × 3, purple
- 8 Blue allium × 10, blue
Why this plant
- The only open bowls. The others are daisies, globes, plumes and others. Shape reads at a distance, where colours blur.
- The only yellow. The one hot colour: every other flower here is cool or neutral.
- The only medium leaves here. The rest are fine and bold. A change of leaf keeps plants distinct when nothing is in flower.
Why here
- In the middle. At 18 in it is the step between silver sage (12 in) in front and wallflower 'Bowles's Mauve' (2½ ft) behind: each is seen over the one before.
- 3 plants in one group. Massed, one kind reads as a single shape. Scattered, it would look spotty.
Why now
- In flower for 7 weeks. From late May to mid July.
- Part of the bed's peak. With sea thrift, wallflower 'Bowles's Mauve', allium 'Ambassador' and others in early June: 5 kinds at once. No week has more.
Planned as a naturalistic planting: low grasses and groundcovers, the matrix, make up 45% of the planted ground. Heath aster 'Snow Flurry' is planted in three places along the bed, which gives it rhythm. Wallflower 'Bowles's Mauve' flowers longest, for 26 weeks.
The planner's own design check: 14 Excellent, 3 Good. 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 sundrops goes in a border
At 18 in it belongs at the front of a bed. In the planner's ten height classes it is short (12 to 18 in).
Its job: drift. Planted in a small group of three or five, and repeated further along in the other number.
A cheerful, tough old cottage plant that opens by day, unlike the evening primroses. It spreads into a patch, but the shallow rosettes are easy to pull.
- Bright yellow for dry, sunny beds
- Cottage gardens
- Slopes
What to plant with sundrops
Plants recorded as good partners for it, and what each pairing does:
- Salvia 'May Night': purple against yellow, opposite each other on the colour wheel, in flower together for seven weeks.
- Catmint 'Walker's Low': in flower together for seven weeks, from late May; happy in the same dry soil.
- Butterfly weed: in flower together for three weeks, from late June; happy in the same dry soil.
Questions about sundrops
Does sundrops need sun or shade?
Sundrops 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 dry, sharply drained soil, of average fertility, and little watering once settled. Once settled in, it stands drought.
What zones does sundrops 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 sundrops flower in my zone?
In zone 5 it flowers late May to mid July. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 4 | Early June to mid July |
|---|---|
| Zone 5 | Late May to mid July |
| Zone 6 | Late May to mid July |
| Zone 7 | Mid May to early July |
| Zone 8 | Early May to early July |
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 sundrops 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 18 in (45 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many sundrops 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 sundrops 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 sundrops?
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 sundrops spread?
It spreads sideways, by runners or roots; the risk of it taking over is moderate. Spreads by underground runners and can crowd its neighbours. Dig out the edges or divide every 2 to 3 years.
What flowers after sundrops?
Sundrops is over by mid July. 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.
- Black-eyed Susan: from mid July to mid September, 24 in tall.
- Ornamental onion 'Millenium': from mid July to late August, 18 in tall.
What does sundrops look like in winter?
Sundrops holds some of its leaves into winter, more in a mild year or a sheltered spot, and they look tired by March. Cut the old ones off as new growth starts.
Is sundrops good for bees and butterflies?
Sundrops is visited by pollinators, specialist bees, hummingbirds and songbirds.
It is native to the United States and Canada.
More Oenothera
- Gaura 'Siskiyou Pink' Oenothera lindheimeri 'Siskiyou Pink'
- Gaura 'Whirling Butterflies' Oenothera lindheimeri 'Whirling Butterflies'
- Missouri evening primrose Oenothera macrocarpa
- Pink evening primrose Oenothera speciosa
- Sundrops 'Fireworks' Oenothera fruticosa 'Fyrverkeri'
In these guides
- Deer-resistant perennials for full sun
- Drought-tolerant perennials for full sun
- Pet-safe plants for a sunny border
- Native perennials for pollinators
- Garden plants native to Canada
- Plants for hummingbirds
- Plants for bees
- Plants that feed garden birds
Every fact on record
- Type
- Perennial
- Size
- 18 in (45 cm) tall, 18 in (45 cm) wide
- Plant
- 18 in (45 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- Late May to mid July; open bowls; yellow
- Leaves
- Medium texture, semi-evergreen; green
- Shape
- Upright, spreading
- Hardy in
- USDA zones 4 to 8
- Light
- Full sun, part sun
- Soil
- Average, dry and sharply drained
- Water
- Low
- Feeding
- None needed
- Family
- Onagraceae
- Comes from
- Eastern North America
- Attracts
- Pollinators, specialist bees, hummingbirds, songbirds
- Stands up to
- Deer, drought, heat, poor soil
Checked against NC State Extension 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.