Lobularia maritima 'Rosie O'Day'
‘Rosie O’Day’ is a pink sweet alyssum that opens nearly white and ages to rosy pink with a small yellow eye. Plants are low and spreading and make a neat edging in cool weather. The honey scent is strong and attractive to small pollinators. Flowering is best in spring and autumn and may slow in the warmest weeks of summer. It is often paired with white alyssum to form two‑tone carpets along paths and in containers.
At‑a‑glance
- Group/Class: sweet alyssum seed cultivar
- Height × spread: 3 to 6 in (8 to 15 cm) × 10 to 12 in (25 to 30 cm)
- Bloom window: spring to frost in cool conditions
- Color & flower form: white to pink with yellow eye; rounded clusters of tiny flowers
- Fragrance: 3 strong
- USDA hardiness: grown as annual in most of North America
- Breeder / Year / Origin: unknown
- Awards/registration: RHS Award of Garden Merit
- Pet safety: safe
How it differs
- Distinct pink tones compared with standard white selections.
- Color shift from white to pink increases depth in mass plantings.
- Compact habit suited to edging and small containers.
Strengths
- AGM recognition for reliable garden value.
- Strong fragrance and steady bloom in cool weather.
- Useful mixer with white alyssum for soft contrasts.
Care in one minute
- Choose full sun in cool‑summer areas or light afternoon shade in hot regions.
- Plant in well‑drained soil that is average in fertility and neutral to slightly alkaline (6.0 to 8.0).
- Water regularly during establishment and in prolonged dry spells; allow the surface to dry between waterings.
- Feed lightly at planting; too much nitrogen reduces bloom.
- Shear or deadhead after the first flush to prompt rebloom and keep plants compact.
- Treat as annual in most of North America; remove before winter or allow limited self‑seeding.
Watch‑outs
- Flowering can stall in high heat; cut back and water to encourage rebloom.
- Seedlings are susceptible to damping‑off in overly wet media.
- Can self‑sow; remove spent plants if reseeding is not desired.
Best uses (tags)
edging; borders; containers; pollinators; cool‑season color
Provenance note
‘Rosie O’Day’ is a long‑grown seed selection of *Lobularia maritima* that earned RHS Award of Garden Merit status.
Written by: Your Flowers Guide editorial team
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