Yellow corydalis
Pseudofumaria lutea ·
Mounds of ferny, blue-green leaves carry small yellow, tubular flowers from May to September. It seeds itself into walls, steps and paving cracks.
- Size
- 14 in tall, 14 in wide
- Zones
- 5 to 7
- Light
- Part sun to shade
- Flowers
- Early May to mid September
- Pets
- Not checked
- Job in a bed
- Weaver
A bed built around yellow corydalis
The planner designed this bed around yellow corydalis when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden in zone 6, part shade. It chose the other plants from the 513 that suit those conditions, and says below why yellow corydalis stands where it does.
The plants
- 1 Yellow corydalis × 4, yellow
- 2 Creeping mahonia × 8, yellow
- 3 White barrenwort 'Niveum' × 10, white
- 4 Blue wood aster × 3, lavender
- 5 Foxglove × 4, purple
- 6 Bleeding heart × 1, pink
- 7 Giant snowdrop × 12, white
- 8 Glory-of-the-snow × 12, blue
Why this plant
- The only fine leaves here. The rest are medium and bold. A change of leaf keeps plants distinct when nothing is in flower.
Why here
- Near the front. At 14 in it stands ahead of blue wood aster (3 ft) without hiding it.
- 4 plants in 4 places. An accent is a punctuation mark: the repeat along the bed gives it rhythm.
- Fine leaf against bold. Foxglove is beside it: the strongest contrast of leaf there is.
Why now
- In flower for 20 weeks. From early May to mid September.
- Fills a gap. For 8 of those weeks nothing else on the plan is in flower.
Planned as a cottage garden: 30 of the 30 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. Foxglove and blue wood aster anchor the back corners of the bed: the tallest plants on the plan stand there. The scheme leans cool (lavender, purple, pink and blue) and uses yellow for warmth, with white to calm things between them.
The planner's own design check: 12 Excellent, 5 Good.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where yellow corydalis goes in a border
At 14 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: weaver. A light, airy plant threaded singly between sturdier ones to knit the planting together.
Few shade plants flower for five months. Let it put itself where it likes: in the cracks of a wall or along a shady path it looks as if it has always been there. Unwanted seedlings pull out easily.
- Flowers all summer in shade
- Softening walls and steps
- Dry shade
What to plant with yellow corydalis
Plants recorded as good partners for it, and what each pairing does:
- Hosta: its green leaves are a setting for the flowers, before and after; bold leaves against its fine ones; spires rising out of its mound.
- Lenten rose: bold leaves against its fine ones.
- Japanese painted fern: its silver leaves are a setting for the flowers, before and after.
Questions about yellow corydalis
Does yellow corydalis need sun or shade?
Yellow corydalis grows in part sun (4 to 6 hours of sun, including some afternoon sun), part shade (2 to 4 hours of sun, mostly in the morning) and shade (less than 2 hours of direct sun, or bright dappled light).
It wants ordinary well-drained soil, of average fertility, and little watering once settled.
What zones does yellow corydalis grow in?
USDA zones 5 to 7. It is hardy to zone 5, which means it survives winter nights down to about −10 °F (−23 °C).
Above zone 7 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 yellow corydalis flower in my zone?
In zone 5 it flowers early May to mid September. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 5 | Early May to mid September |
|---|---|
| Zone 6 | Early May to mid September |
| Zone 7 | Late April to mid September |
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 yellow corydalis be planted?
12 in (30 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 14 in (35 cm), so a group knits into one patch.
It grows 14 in (35 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many yellow corydalis plants do I need?
At 12 in apart, set out in staggered rows:
- 12 to fill 10 square feet (about 1 m²)
- 11 for a single row 10 ft (3 m) long
- 38 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one at a time, threaded between sturdier plants.
In the bed above, the planner used four in four groups.
Is there a native plant like yellow corydalis?
Yellow corydalis is not native to North America. These North American natives come closest to doing its job:
- Wild columbine: the same job in a bed; belongs in the middle, not at the front, 10 in taller.
- Celandine poppy: the same size and the same colour; a drift, not a weaver, flowers mid April to late May.
- Creeping Jacob's ladder: the same size; a drift, not a weaver, flowers late April to late May.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
Will yellow corydalis spread?
It seeds itself about; the risk of it taking over is moderate. Self-seeds freely. Remove the spent flowers to limit seedlings.
What flowers after yellow corydalis?
Yellow corydalis is over by mid September. These start as it finishes and carry the same spot on, so it never goes flat:
- October daphne: from mid September to late October, 8 in tall, to stand in front of it and cover its fading stems.
- Meadow saffron: from mid September to mid October, 6 in tall, to stand in front of it and cover its fading stems.
- Autumn crocus: from mid September to mid October, 5 in tall, to stand in front of it and cover its fading stems.
What does yellow corydalis look like in winter?
Yellow corydalis 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.
In these guides
Every fact on record
- Type
- Perennial
- Size
- 14 in (35 cm) tall, 14 in (35 cm) wide
- Plant
- 12 in (30 cm) apart
- Height class
- Short (12 to 18 in)
- Place in the bed
- Front
- Flowers
- Early May to mid September; dense clusters; yellow
- Leaves
- Fine texture, herbaceous; blue-green
- Shape
- Mounding, self-seeding
- Hardy in
- USDA zones 5 to 7
- Light
- Part sun, part shade, shade
- Soil
- Average, well-drained
- Water
- Low
- Feeding
- None needed
Not yet checked against an outside reference: its figures rest on general horticultural knowledge. 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.