Native Plants

Sea Milkwort

Glaux maritima

USDA symbol: GLMA

perennial forb

Alaska: native
Canada: native
Lower 48 states: native
St. Pierre and Miquelon: native

If you’ve ever wandered along a salt marsh or coastal wetland, you might have spotted a diminutive plant with succulent-like leaves hugging the ground. Meet sea milkwort (Glaux maritima), a plucky little perennial that thrives where most plants would throw in the towel. This hardy native forb has mastered the ...

Sea Milkwort may be listed as rare in your area.
New Jersey

Status: Highlands Listed, SX.1 | Presumed extinct: Not located despite intensive searches. Unlikely to be rediscovered.

Sea Milkwort: A Tiny Coastal Native with Big Attitude

If you’ve ever wandered along a salt marsh or coastal wetland, you might have spotted a diminutive plant with succulent-like leaves hugging the ground. Meet sea milkwort (Glaux maritima), a plucky little perennial that thrives where most plants would throw in the towel. This hardy native forb has mastered the art of coastal living, making it both fascinating and challenging for home gardeners.

What Is Sea Milkwort?

Sea milkwort is a low-growing perennial forb native to Alaska, Canada, and much of the lower 48 states. Despite its name, it’s not actually related to the milkwort family – it’s a member of the primrose family that just happens to share a common name. This little plant rarely grows taller than about 0.9 feet, instead preferring to spread horizontally and form dense mats.

The plant produces small, white flowers in late spring that, while not particularly showy, add a delicate touch to its succulent-like foliage. The leaves are small, oval, and fleshy – perfectly adapted for life in salty conditions.

Where Does Sea Milkwort Grow?

This coastal native has an impressive range, growing naturally across much of North America from Alaska down through Canada and into many U.S. states including California, Colorado, Idaho, Maine, Maryland, Massachusetts, Minnesota, Montana, and many others. You’ll find it primarily in coastal salt marshes, alkaline wetlands, and other saline environments.

  • Species observed
  • No observations

The Rarity Factor

Before you get too excited about adding sea milkwort to your garden, there’s something important to know: this species is quite rare in some areas. In New Jersey, for example, it’s listed as Highlands Listed, SX.1, indicating significant conservation concern. If you’re interested in growing sea milkwort, it’s crucial to source it responsibly from reputable native plant nurseries that don’t collect from wild populations.

Why Grow Sea Milkwort?

Sea milkwort isn’t your typical garden center find, and honestly, that’s probably for the best. This specialized plant is perfect for very specific situations:

  • Coastal properties with salt spray and alkaline soils
  • Salt marsh restoration projects
  • Specialized rock gardens with saline conditions
  • Erosion control in challenging coastal environments
  • Educational or demonstration gardens focused on wetland ecology

The plant offers some benefits to small pollinators, attracting flies and tiny bees to its modest white blooms. However, don’t expect it to be a pollinator powerhouse – think of it more as a supporting player in your coastal ecosystem.

Growing Conditions: Not for the Faint of Heart

Let’s be honest – sea milkwort is not an easy plant to grow, and it’s definitely not suitable for typical garden conditions. This plant has very specific needs:

  • Soil: Requires alkaline to highly alkaline soils (pH 6.5-8.8) with good salt tolerance
  • Moisture: Needs consistently high moisture – it’s classified as an obligate wetland plant in most regions
  • Sun: Full sun only – shade intolerant
  • Hardiness: Zones 3-8, can handle temperatures down to -33°F
  • Salt tolerance: Thrives in saline conditions that would kill most plants

Planting and Care Tips

If you’re determined to try growing sea milkwort (and you have the right conditions), here’s what you need to know:

  • Seeds: Can be propagated from seed, but expect slow establishment and low seed production
  • Soil preparation: Ensure excellent drainage while maintaining consistent moisture – think salt marsh, not bog
  • Fertilization: Keep it minimal – this plant prefers low-fertility conditions
  • Patience: Growth rate is moderate, and the plant spreads slowly
  • Commercial availability: Currently no known commercial sources, making it extremely difficult to obtain

The Bottom Line

Sea milkwort is undeniably cool – a tough little native that’s mastered one of the most challenging environments on Earth. But unless you have coastal property with naturally saline conditions, or you’re involved in salt marsh restoration, this probably isn’t the plant for you.

For most gardeners interested in native wetland plants, consider alternatives like blue flag iris, swamp milkweed, or cardinal flower, which are easier to grow and more widely available. But if you do have the perfect spot and can source it responsibly, sea milkwort offers a unique glimpse into the specialized world of halophytic (salt-loving) plants.

Remember, this little plant has been perfecting its coastal lifestyle for thousands of years – respect its needs, and it just might reward you with its quiet, resilient beauty.

Glaux maritima is also known as...

Often we refer to plants by their common names. When shopping for plants the scientific name is the best way to positively identify the plant species you desire. But some plants have more than one name! While it doesn't happen often, nurseries might display one name while you're searching for another. Glaux maritima is also known as:

Glaux maritima var. angustifolia | USDA symbol: GLMAA2
Glaux maritima var. macrophylla | USDA symbol: GLMAM2
Glaux maritima var. obtusifolia | USDA symbol: GLMAO
Glaux maritima ssp. obtusifolia | USDA symbol: GLMAO2
Lysimachia maritima Galasso, Banfi & | USDA symbol: LYMA11

Why do some plants have more than one name? Over time plant species may be renamed for a few reasons:

  1. Botanists in different regions named the same plant without knowing it had already been classified.
  2. A species was reclassified after scientific advances in, for example, DNA analysis.
  3. Slight variations within a species are sometimes mistakenly identified as entirely new species.

Classification

Group: Dicot
Kingdom: Plantae - Plants
Subkingdom: Tracheobionta - Vascular plants
Superdivision: Spermatophyta - Seed plants
Division: Magnoliophyta - Flowering plants
Class: Magnoliopsida - Dicotyledons
Subclass: Dilleniidae
Order: Primulales
Family: Primulaceae Batsch - Primrose family
Genus: Glaux L. - milkwort

Species: Glaux maritima L. - sea milkwort

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA