Carpeting the Garden in Living Green

A favorite look in many gardens is flagstone surrounded by a carpet of ground covers. Providing exciting textures and colors, the shortest of the short such as creeping thyme, Corsican mint, Irish and Scotch moss, and others cover the soil as they crawl over and furnish a cohesive element in the garden.

These plants provide textural interest as edging along walkways or in between stepping stones and pavers. In addition, many of these plants creep or romp around the garden and surround more substantial vegetation. For plants that grow an inch or two above the soil, it’s surprising how much visual impact they can have.

Woolly thyme (Thymus pseudolanuginosus)

Woolly thyme (Thymus pseudolanuginosus)

Some great choices for pathways are the favorite ground-covering thyme. When stepped on, their spicy thyme fragrance releases into the air. Walk barefoot down a path covered in low-growing thyme and find it’s good for the soul and the soles.

Several cultivars and species do a fantastic job covering the ground. Thyme is drought tolerant, essential for xeric gardens in the rain shadow areas on the peninsula. When planted under full sun, in well-drained soil, they are carefree plants once established.

Woolly thyme (Thymus pseudolanuginosus) is low-growing thyme. Its miniature, aromatic foliage covered in fine hairs gives the green leaf a soft, fuzzy, silvery gray-green semblance. Don’t let its delicate appearance fool you; it’s a robust little herb that will grow with low maintenance. It’s charming when it drapes down rock walls like a cascading waterfall.

Elfin thyme (Thymus serpyllum ‘Elfin’)

For tiny-leaf thyme, try elfin thyme (Thymus serpyllum ‘Elfin’), sometimes sold locally as T. minus and T. ‘Minimus’. The minuscule, evergreen leaves tightly packed together form a dense mat, which outlines the space between flagstones in a deep-green hue.

With less foot traffic, this small herb creeps over and covers the stones. Superb growing on top of a rock wall, the tiny-leaf plant trails down and softens the hard edges between the rocks. Then, every summer for a few weeks, the plant covers itself with tiny purple flowers.

(Thymus serpyllum ‘Elfin’) syn. T. minus and T. ‘Minimus’

Baby tears (Soleirolia soleirolii)

Baby tears (Soleirolia soleirolii), another Mediterranean plant, grows well in our climate and spreads indefinitely. In some local gardens, it can circle around small Chiastophyllums and will cozy up to ferns, shrubs, and trees. This plant often spills down rock walls onto a gravel pathway below.

It isn’t foot-friendly on the main path, however. The less traffic on the ground cover, the lusher it looks. Baby tears die back to the ground during a hard freeze; however, it faithfully returns in spring. Drought tolerant during West Sound’s rain-less summers, it’s a choice plant for xeriscapes.

Blue star creeper (Isotoma fluviatilis)

A prime plant for between pavers is the charming blue star creeper — Isotoma fluviatilis, sometimes sold as Pratia pedunculata or Laurentia fluviatilis.

Another prime plant between pavers is the charming blue star creeper — Isotoma fluviatilis, sometimes sold as Pratia pedunculata or Laurentia fluviatilis. This semi-evergreen, tiny-leaf plant cloaks itself with small, sky-blue, star-shaped flowers from late spring into summer and continues with a sprinkling of blossoms for the rest of the season into fall.

The ‘Deep Blue’ cultivar is a favorite for darker blue flowers that don’t fade.

Blue star creeper requires well-drained soil and full sun for best results. The downside to growing this ground cover is that it can crowd out some small plants. So site it carefully where it can romp around, adding spectacular effects in the garden. You can find other cultivars that flower in hues of light blue, dark blue and white.

Blue star creeper (Isotoma fluviatilis)

Corsican mint (Mentha requienii). 

Louise Beebe Wilder once wrote about the mini Corsican mint (Mentha requienii), calling it a “powerfully fragrant microscopic mint, useful for carpeting dampish places.” 

Unlike many other plants from dry summer areas, this plant needs regular watering and will die back if not watered enough. Although evergreen during mild winters, for the most part, Corsican mint is deciduous. 

The plant will take light foot traffic, making it suitable for growing between pavers and in the garden. 

Corsican mint (Mentha requienii)

Sagina subulata

Scotch moss (Sagina subulata ‘Aurea’) is a cultivar with striking chartreuse foliage, and the species Irish moss (Sagina subulata) is a lovely, vibrant green.

Sagina subulata species and cultivars grow so dense, it forms small hummocks.

Irish moss (Sagina subulata) is on the right. Scotch moss (Sagina subulata ‘Aurea’) is on the left.

Although Irish moss (Sagina subulata) is not a moss, it is a lovely, vibrant green perennial that grows to perfection between pavers and stones. The plant spreads indefinitely and becomes dense forming small hummocks. You can leave this for additional interest in the garden, or you can cut an x in the mound and push it back down to the ground.

Scotch moss (Sagina subulata ‘Aurea’) is a cultivar with striking chartreuse foliage.

There is nothing like a little green mondo grass (Ophiopogon japonicus var. compacta) to pave the way between stones. It looks like grass from the lawn with a thicker blade, but it is actually a member of the lily family.

Cultivars such as Ophiopogon ‘Nippon'” grow 2 inches tall and O.’ Super Dwarf’ reaches 1 inch tall, filling the spaces between pavers with its no-mow, grass-like foliage. Its clumping habit makes it easy to keep up after; however, purchase and plant more of these initially to cover the ground, as they slowly spread only a few inches wide each year.

A half-buried strawberry pot planted with hen & chicks (Sempervivum) is surrounded by the ground covering Sedum acre.

Originally published in West Sound Home & Garden — May/June 2015.