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Annual Biennial
Blackstonia perfoliata
yellowwort
An annual to 40cm tall, mainly found on chalky and limestone grasslands, sand dunes and in rocky places, with waxy, grey to bluish-green opposite pointed leaves fused around the stem. Butter yellow, cup-shaped flowers with 6 to 8 petals, closing in the afternoon, are produced in summer and autumn
Size
Ultimate height
0.1–0.5 metresTime to ultimate height
1–2 yearsUltimate spread
0.1–0.5 metresGrowing conditions
Chalk
Loam
Sand
Moisture
Well–drainedpH
Alkaline, NeutralColour & scent
| Stem | Flower | Foliage | Fruit | |
| Spring | Grey Silver Blue Green | |||
|---|---|---|---|---|
| Summer | Yellow | Grey Silver Blue Green | ||
| Autumn | Yellow | Grey Silver Blue Green | ||
| Winter |
Position
- Full sun
Aspect
South–facing or West–facing
Exposure
Exposed or Sheltered Hardiness
H7Botanical details
- Family
- Gentianaceae
- Native to the UK
- Yes
- Habit
- Clump forming
- Name status
Correct
How to grow
Cultivation
Grow in well-drained neutral to alkaline soil in full sun; a good coastal plant
Propagation
Propagate by seed
Suggested planting locations and garden types
- Coastal
- Cottage and informal garden
- Wildflower meadow
- Wildlife gardens
Pruning
No pruning required
Pests
Generally pest-free
Diseases
Generally disease-free
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