Yellow false indigo
Baptisia sphaerocarpa ·
Bright yellow pea flowers on upright spikes in late spring, followed by round seed pods, on a compact, drought-proof dome.
- Size
- 3 ft tall, 3 ft wide
- Zones
- 5 to 9
- Light
- Full sun
- Flowers
- Late May to late June
- Pets
- Toxic to people
- Job in a bed
- Specimen
A bed built around yellow false indigo
The planner designed this bed around yellow false indigo when this page was made: a 12 × 6 ft (3.7 × 1.8 m) cottage garden 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 yellow false indigo stands where it does.
The plants
- 1 Yellow false indigo × 1, yellow
- 2 Cheddar pinks 'Tiny Rubies' × 16, pink
- 3 Heath aster 'Snow Flurry' × 5, white
- 4 Prairie blazing star × 4, purple
- 5 Slender mountain mint × 3, white
- 6 Schubert's allium × 4, pink
- 7 Triteleia 'Queen Fabiola' × 12, blue
Why this plant
- The only yellow. The one hot colour: every other flower here is cool or neutral.
- The only medium leaves here. The rest are fine. A change of leaf keeps plants distinct when nothing is in flower.
Why here
- Anchors a back corner. At 3 ft it is one of the taller plants here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to prairie blazing star (4 ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A feature plant is seen as an object, and needs clear ground around it.
Why now
- In flower for five weeks. From late May to late June.
- Part of the bed's peak. With Cheddar pinks 'Tiny Rubies', Schubert's allium and triteleia 'Queen Fabiola' in mid June: 4 kinds at once. No week has more.
Planned as a cottage garden: 29 of the 29 plants (100%), bulbs aside, stand alone or in groups of no more than five, small enough for the kinds to mingle. The flowering is at its height from mid June, with 4 kinds out together. Cool colours (pink, purple and blue) with yellow as the warm note, and white to calm things between them.
The planner's own design check: 10 Excellent, 7 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 yellow false indigo goes in a border
At 3 ft it belongs in the middle of a bed. In the planner's ten height classes it is medium tall (2½ to 3 ft).
Its job: specimen. A feature plant with a shape of its own. It stands alone with room around it, and repeats only at a distance.
The smallest and most drought-tolerant false indigo. Its clear yellow is best with blues: bluestar, salvia or catmint.
- Yellow spires for hot, dry sites
- Native planting
- A compact false indigo for smaller beds
What to plant with yellow false indigo
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 four weeks; spires rising out of its mound.
- Catmint 'Walker's Low': in flower together for five weeks, from late May; a low mound at the foot of its spires; happy in the same dry soil.
- Bluestar: blue against yellow, opposite each other on the colour wheel, in flower together for four weeks; a low mound at the foot of its spires.
Questions about yellow false indigo
Does yellow false indigo need sun or shade?
Yellow false indigo grows in full sun (6 or more hours of direct sun a day).
It wants dry, sharply drained soil, of average fertility, and little watering once settled.
What zones does yellow false indigo 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 yellow false indigo flower in my zone?
In zone 5 it flowers late May to late June. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 5 | Late May to late June |
|---|---|
| Zone 6 | Mid May to late June |
| Zone 7 | Early May to mid June |
| Zone 8 | Early May to mid June |
| Zone 9 | Late April to early June |
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 false indigo be planted?
3 ft (90 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 3 ft (90 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many yellow false indigo plants do I need?
At 3 ft apart, set out in staggered rows:
- 1 to fill 10 square feet (about 1 m²)
- 4 for a single row 10 ft (3 m) long
- 4 to fill a 4 × 8 ft bed on its own
In a mixed border, plant it as one, with clear ground around it: a feature plant is seen as an object, and a group of them is a thicket.
In the bed above, the planner used one in one group.
Is yellow false indigo poisonous?
Yes: mild toxicity to people. May cause mild stomach upset if eaten.
What flowers after yellow false indigo?
Yellow false indigo is over by late June. These start as it finishes and carry the same spot on, so it never goes flat:
- Black-eyed Susan: from mid July to mid September, 24 in tall, to stand in front of it and cover its fading stems.
- Butterfly weed: from late June to early August, 24 in tall, to stand in front of it and cover its fading stems.
- Daylily: from late June to early August, 2½ ft tall.
What does yellow false indigo look like in winter?
Yellow false indigo 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.
More Baptisia
- Blue false indigo Baptisia australis
- False indigo 'Carolina Moonlight' Baptisia 'Carolina Moonlight'
- False indigo 'Lemon Meringue' Baptisia 'Lemon Meringue'
- False indigo 'Purple Smoke' Baptisia 'Purple Smoke'
- White false indigo Baptisia alba
In these guides
Every fact on record
- Type
- Perennial
- Size
- 3 ft (90 cm) tall, 3 ft (90 cm) wide
- Plant
- 3 ft (90 cm) apart
- Height class
- Medium tall (2½ to 3 ft)
- Place in the bed
- Middle
- Flowers
- Late May to late June; upright spires; yellow
- Leaves
- Medium texture, herbaceous; blue-green
- Shape
- Mounding, clumping
- Hardy in
- USDA zones 5 to 9
- Light
- Full sun
- Soil
- Average, dry and sharply 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.