Herniaria glabra [her-nee-AR-ee-uh, GLAY-bruh] is a hardy, low growing groundcover known as Rupturewort, Smooth Rupturewort or simply, Green Carpet.
This perennial plant is a member of the Caryophyllaceae family and native to North Africa, western Asia, and parts of Europe.
Herniaria Glabra Care
Size & Growth
This slow-growing, bright green creeper has a spread of approximately 2’ feet.
It makes an excellent groundcover because it only grows to a height of about 3″ inches.
When planting, be sure to give each plant at least a square foot of space to spread.
Rupturewort’s leaves are tiny and dense. When handled or stepped upon, they emit an interesting musky smell.
The leaves are lime green throughout the growing season.
They transition into shades of bronze, red, and maroon late in autumn for impressive winter interest.
Flowering & Fragrance
Early in the summer and through mid-July, Green Carpet produces massive numbers of extremely tiny, nearly unnoticeable white or yellowish-green flowers.
These flowers are so inconspicuous and insignificant; they do not even attract bees.
You may never know when your plants are in bloom.
Light & Temperature
This carefree groundcover does best in full sunlight, but it can tolerate partial shade.
If planted in full shade, it will not do well at all.
Smooth Rupturewort is winter hardy in USDA hardiness zones 6 through 10.
Watering & Feeding
Even though Green Carpet only grows to be about 3″ inches high, each plant has an extremely long taproot.
For this reason, this rugged groundcover is quite drought tolerant and is an excellent choice for xeriscaping.
Water deeply, occasionally, if at all. Take care not to water excessively.
When you initially plant young Rupturewort, give it a light feeding of general-purpose fertilizer.
If your soil is fairly decent, this is not at all necessary.
Once established, these plants need no fertilizer at all.
Soil & Transplanting
Herniaria glabra is so rugged it can even grow in fine gravel.
It does well in hot, dry soil and makes a superb groundcover for areas with very poor soil.
It will not tolerate soggy soil.
Grooming & Maintenance
Once established, this smooth, green living carpet is maintenance-free.
How To Propagate Rupturewort
It’s easy to propagate Green Carpet by sowing the seed directly onto the surface of the soil you wish to cover.
A package of five thousand seeds will cover about one hundred square feet.
Ideal conditions include a consistent temperature of about 68° degrees Fahrenheit (20° C), good sun exposure, and warm soil kept slightly moist until the seeds have germinated and grown into tiny plants.
Once established, rupturewort is self-seeding.
If you wish, sow the seed indoors or in a cold frame in autumn.
When the seedlings are large enough to handle, give each one an individual pot and keep them indoors or in a greenhouse through their first winter.
Once all danger of frost has passed, transplant them to their permanent settings.
Rupturewort Pest or Disease Problems
This happy-go-lucky groundcover experiences no insect or disease problems under ideal conditions.
Soggy soil will cause root rot.
Excessive shade will cause failure to thrive.
Is The Glabra Plant Toxic or Poisonous?
Although Herniaria glabra is not listed as toxic, it is a medicinal plant possessing astringent, diuretic, and expectorant qualities.
Extracts of the plant are used to treat bladder problems, dropsy, cystitis, and kidney stones.
As with any medicinal plant, care should be taken not to ingest it or expose large expanses of skin to it.
Be sure to wash up after handling, and even though it is a steppable plant, don’t make a habit of lolling about on it.
Is Green Carpet Invasive?
Although green carpet is not listed as invasive, it does have quite a bit of weed potential.
It spreads easily and self-seeds and thrives in poor soil.
For this reason, it’s wise to keep an eye on it and don’t allow it to escape your garden setting.
Suggested Herniaria Glabra Uses
Green Carpet Herniaria is a nearly indestructible, carefree groundcover making an excellent lawn substitute and is pretty and interestingly fragrant planted between flagstones.
This deer-resistant evergreen groundcover is soft underfoot and provides interesting texture and form as edging, in an Alpine garden, or a rock garden.
Plant it in your bulb garden to provide interest, color, and living mulch.
Your bulbs can easily grow up through the pretty green mat when they are ready.
Individual plants are also interesting in containers, but take care to provide plenty of room for the taproot, or plan to transplant when the Rupturewort matures.