Kerria
Kerria japonica
Shade suits it, feeding does not, and the only real work is keeping the suckers in hand.
- Type
- Shrub · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Yellow
- Sunlight
- Full sun through to deep shade.
- Watering
- Drought-tolerant once established.
- Feeding
- Rarely needed.
- Frost tolerant
- Yes
- Flowering
- April
- Pruning
- Cut it back hard as soon as the flowers finish.
- Overwintering
- Fully hardy — no winter protection needed.
- Mar–Mar Bud Break
- Mar–Apr Spring Growth
- Apr–Jun Flowering
- Jun–Nov Growing
- Nov–Dec Leaf Fall
- Jan–Mar Leaf Fall
- Plant spacing
- 5 ft 11 in
- In-row spacing
- 5 ft 11 in
- Between rows
- 7 ft 5 in
- Square-foot density
- Not suited to SFG
- Root system
- Woody and fibrous
- Working depth
- 12–24 in
- Can reach
- 3 ft down where the soil allows
- Spread
- 9–12 ft across, about 1.5–2× the width of the plant
- Shallowest pot
- 20 in of soil
A shallow woody framework with the fine feeding roots in the leaf litter above it. Those feeders are mostly under the outer half of the canopy rather than against the stem, which is where water and feed should go.
Suckers vigorously into a thicket, spreading well beyond where it was planted. It is a good shrub for a difficult shaded corner and a poor one for a tidy border.
The habit is Kerria’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Blight Leaf blight through wet summers
- Suckers coming up where they are not wanted
Shrubs, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com