Prostrate Sandmat: A Tough Little Ground Cover That’s Not for Everyone
Meet prostrate sandmat (Chamaesyce prostrata), a humble little plant that goes by many names—blue weed, ground spurge, or prostrate spurge. This small but mighty ground hugger might not win any beauty contests, but it’s got some serious survival skills that make it both useful and potentially problematic in the garden.
What Is Prostrate Sandmat?
Prostrate sandmat is a low-growing annual or perennial forb that forms spreading mats across the ground. It’s a member of the spurge family and produces a milky sap when broken (watch out—this can be irritating to skin). The plant features small, oval leaves on reddish stems and produces tiny, inconspicuous flowers that develop into small seed capsules.
Don’t expect this plant to steal the show in your flower border. Its charm lies in its tenacity rather than its beauty, growing as a prostrate mat that rarely exceeds a few inches in height but can spread several feet wide.
Where Does It Come From?
Here’s where things get interesting: prostrate sandmat is native to most of the continental United States, Puerto Rico, and the U.S. Virgin Islands. You can find it naturally occurring from Alabama to Wyoming, and from Massachusetts to California. However, it’s considered non-native in Hawaii and some Pacific territories, where it has established itself quite successfully.
Should You Plant Prostrate Sandmat?
This is where prostrate sandmat gets complicated. While it’s native to most areas and can be useful in specific situations, it’s also a vigorous self-seeder that can quickly take over areas where you might not want it.
Reasons You Might Want It:
- Excellent for covering difficult, disturbed soils
- Extremely drought tolerant once established
- Requires virtually no maintenance
- Helps prevent soil erosion on slopes
- Provides habitat for small beneficial insects
- Native to most of the United States
Reasons You Might Not:
- Can be aggressively weedy and hard to control
- Not particularly attractive or ornamental
- May crowd out more desirable plants
- Difficult to remove once established
- Produces irritating milky sap
Growing Conditions and Care
If you decide prostrate sandmat fits your needs, you’ll find it’s one of the easiest plants to grow—perhaps too easy! This tough little survivor thrives in USDA hardiness zones 4-11 and adapts to a wide range of conditions.
Ideal Growing Conditions:
- Sunlight: Full sun to partial shade
- Soil: Poor to average soil; extremely adaptable to soil pH
- Water: Drought tolerant; actually prefers drier conditions
- Maintenance: Virtually none required
Prostrate sandmat typically grows in upland areas rather than wetlands, though it can occasionally pop up in wetter spots depending on your region.
Best Uses in the Garden
Think of prostrate sandmat as nature’s patch kit for problem areas. It’s perfect for:
- Rock gardens and xeriscaping projects
- Covering disturbed or compacted soil
- Filling gaps in pathways or between pavers
- Erosion control on slopes
- Areas where nothing else will grow
Just remember: this plant has a mind of its own when it comes to spreading. Use it in areas where you can contain it or where aggressive spreading won’t be a problem.
Planting and Propagation
Here’s the thing about prostrate sandmat—you probably won’t need to plant it intentionally. It’s excellent at finding its own way into gardens through self-seeding. If you do want to establish it, seeds can be scattered in early spring or fall, and they’ll germinate readily with minimal soil preparation.
Once established, expect it to return year after year through prolific self-seeding. The plant produces numerous small seeds that disperse easily, so be prepared for it to show up in unexpected places.
The Bottom Line
Prostrate sandmat is like that friend who’s incredibly reliable but might overstay their welcome. If you have a challenging site where other plants struggle and you don’t mind a somewhat aggressive ground cover, this native plant can be a practical solution. However, if you prefer more control over your garden’s appearance and plant placement, you might want to consider other native alternatives that are less prone to wandering.
For most gardeners, prostrate sandmat is better appreciated as a wild plant doing its job in disturbed natural areas rather than as an intentional garden addition. But in the right spot—say, a gravel driveway or a rocky slope—it might just be the tough, no-nonsense ground cover you never knew you needed.
