The Story
Plant Bio
Kosteletzkya virginica, commonly known as seashore mallow, is a robust, shrub-like herbaceous perennial native to coastal salt marshes of the eastern and southern U.S. It features triangular or arrowhead-shaped, hairy, gray-green leaves and produces solitary, hibiscus-like, typically pink flowers from summer to fall.
'Immaculate' is a popular cultivar distinguished by its pure white flowers, which provide a striking contrast against the gray-green foliage. It retains the species' excellent tolerance for wet soils, salt spray, and clay.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
48 inches
Width
36 inches
Light
Full Sun
Zones
5, 6, 7, 8, 9, 10
Water
Medium to Wet
Humidity
Tolerates high humidity
Lifespan
Perennial
Native To
Eastern and Southern U.S.
Toxicity
Non-toxic to humans and pets
Planting
How to Grow
- Tuck seeds into moist soil in early spring
- Keep soil consistently moist during germination, about 2 weeks
- Transplant seedlings once established to a sunny spot
- Water regularly during dry periods for best growth
- Fertilize with a balanced 10-10-10 fertilizer monthly
- Divide clumps in early spring or fall to propagate
Pro Tip
Use well-draining loamy soil and full sun for optimal flowering.
Keep It Thriving
Care Guide
Do
- Water regularly during dry spells 🌱
- Mulch around plants to retain moisture
- Prune dead or damaged stems in early spring
- Fertilize monthly during active growth
Don't
- Overwater to prevent root rot ❌
- Allow soil to stay waterlogged
- Neglect pruning or deadheading
- Use heavy clay soil without amendment
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deadhead | ||||||||||||
| Divide | ||||||||||||
| Mulch | ||||||||||||
| Plant | ||||||||||||
| Spring Cleanup |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Immaculate Seashore Mallow questions
What zones can Immaculate Seashore Mallow grow in?
Immaculate Seashore Mallow is hardy in USDA Zones 5–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Immaculate Seashore Mallow deer resistant?
Not reliably. Deer may browse Immaculate Seashore Mallow, especially tender spring growth — plan on repellents or fencing where pressure is high.
When does Immaculate Seashore Mallow bloom?
Immaculate Seashore Mallow typically blooms in summer to fall through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Immaculate Seashore Mallow need full sun?
Immaculate Seashore Mallow does best in full sun (6+ hours).
Is Immaculate Seashore Mallow drought tolerant?
Yes — once established (usually after the first full season), Immaculate Seashore Mallow handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Kosteletzkya to compare
Keep exploring
Explore the genus
Grow Immaculate Seashore Mallow with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.