If there’s a universal truth we witness over and over again in the garden, it’s that nature abhors a vacuum.
A gap – any gap – will quickly be filled. Even the tiniest voids you wouldn’t think capable of harboring life will, and they do.
Life finds a way. Like volunteer tomatoes growing out of a crack in the sidewalk while your pampered ones struggle in the garden.
Yup, plants are weird.
One of the most irksome sites for weeds to grow is between the gaps of the hardscape.
Here, in the spaces around stone pathways and patios, dandelions, crabgrass, spurge, plantain, clovers, and prickly thistles will happily grow.
Pull them up, and things will look neat and tidy for a little while. But then, a week or two later, a new wild plant is sure to pop up in the old weed’s place.
The only way to save yourself from this repetitive and fairly pointless task is to physically block them out, so unwanted plants gain no foothold. Fill the vacuum, so to speak, and – voilà – no more weeds in your pavers.
You could use polymeric sand to fill the joints between stones – that’s what most people do. But where’s the green thumbedness in that?
Qualities to Look for in Gap-Filling Plants
Ground-covering plants are wonderful living mulches, protecting bare areas from weeds and looking good while they do it.
When betwixt and between pathway and patio stone, ground covers will soften the edges of the hardscape and tie it in with the greenery of the garden.
Filling in the gaps with dense carpets of lush growth is a charming way to make meandering paths and sitting areas warmer and more inviting places.
With a planted-up hardscape, you can save heaps of cash by leaving larger gaps between the flagstone slabs and blocks. By filling the in-betweens with lovely greenery, there will be fewer stones required to purchase and no need to do time-consuming stone cutting so they fit perfectly together.
But not any ground cover will do as a filler of stone gaps. To be considered “steppable”, plants should have these traits:
A height of no more than 4” tall
Low-growing plants won’t interfere with foot traffic, become tripping hazards, or obscure the beautiful stonework.
Short plants that grow mostly flat to 4 inches in height are the ideal size for interplanting in pavers.
Dense foliage and habit
A plant with dense foliage and a creeping habit will better crowd out the weeds and quickly occupy the spaces between stones.
Paver plants should be vigorous growers that self-propagate in thick mats. Ideally, they’ll be low-maintenance as well and require very little by way of encouragement to spread.
A tough and hardy constitution
These plants should be about as tough as weeds, shrugging off growing conditions that would cause most other cultivars to fade.
To be a steppable ground cover, plants will certainly need to bounce back after being crushed underfoot. Some plants can withstand light foot traffic with the occasional misstep, but others will hold up exceedingly well in heavily-trod pathways.
Another thing to bear in mind is whether your stonework is located in full sun.
The pavers will heat up considerably in a sunny location, so anything planted there should be heat-tolerant and drought-resistant too.
10 Best Ground Covers for Pavers
1. Creeping Thyme (Thymus serpyllum)
Creeping thyme is the traditional stone filler pick, and it surely is one of the finest for adding more color and fragrance to your stepping stones and pathways. It also makes an excellent lawn.
Producing dense and fluffy mounds, 2 to 3 inches tall, creeping thyme spreads by setting down roots along its trailing stems. From June to September, the tiny green elliptical leaves are hidden by masses of deep pink tubular flowers – to the utter delight of bees and butterflies.
Though creeping thyme looks delicate, this plant has a hardy constitution. Native to the dry regions of Northern Europe, it thrives in poor soils and even no soil at all – it will grow on rocks! – and has excellent drought tolerance. All creeping thyme needs in return is lots of sunshine and good drainage.
Plus, it holds up well against occasional to quasi-regular trampling. Crushing, stepping on, and brushing against creeping thyme will release the most delectable herbal, earthy, and slightly minty scent.
Hardiness zone: 4 to 8
Sun exposure: Full sun
Height: 2 to 3 inches
Foot traffic: Moderate
2. Moss Phlox (Phlox subulata)
Moss phlox – or creeping phlox – is a lovely native plant that’s found growing in dry, rocky, and sandy spots in eastern and central North America.
A drought-tolerant creeper, it forms an evergreen carpet of small, narrow, needle-like leaves that average 4 to 6 inches in height. Moss phlox flowers profusely with notched 5-petal blossoms in shades of pink, purple, blue, white, or red, from April to June. In spring, it’s a pollinator magnet, so be careful where you step.
Although moss phlox tolerates light and infrequent traipsing, keep this gorgeous ground cover intact by planting it along the sides and edges of paver paths.
Hardiness zone: 3 to 9
Sun exposure: Full sun
Height: 4 to 6 inches
Foot traffic: Light
3. Blue Star Creeper (Isotoma fluviatilis)
Blue star creeper is another stepping stone favorite, especially in areas with dappled sunlight and moist soil.
Strong, vigorous, and stunning, blue star creeper forms a tightly-knit turf of tiny oblong leaves a half-inch in length. The lovely green carpet is extra wonderful when it blooms with dainty, star-shaped, light blue flowers beginning in early spring and continuing into summer.
Found growing on mud and moist sand along creeks and streams in its Australian homeland, blue star creeper loves wet feet. You’ll have more success growing it in naturally moist and shaded parts of the hardscape.
Hardiness zone: 5 to 9
Sun exposure: Full sun to part shade
Height: 2 to 3 inches
Foot traffic: Moderate
4. Irish Moss (Sagina subulata)
Like a lush emerald green carpet, Irish moss is a compact ground-hugging plant that grows 1 to 2 inches tall.
It has slender feathery leaves that resemble moss, but Irish moss is not a true moss since it bears flowers. These are petite, white, and star-shaped, appearing in late spring and blooming sporadically throughout the growing season.
Between generous self-seeding and creeping stems, Irish moss is quick to fill in spaces around stepping stones and flagstones. The plants are shallow-rooted and prefer even moisture so consider growing Irish moss along partly shaded paths.
Hardiness zone: 4 to 8
Sun exposure: Full sun to part shade
Height: 1 to 2 inches
Foot traffic: Light
5. Green Carpet (Herniaria glabra)
Living up to its name, green carpet is a sprawler that grows close to the ground in thick mats. With foliage soft enough to step on with bare feet, the leaves are small and ovate with fleshy, succulent stems.
Also known as rupturewort, green carpet is an evergreen plant that transitions to reddish bronze over winter.
Green carpet grows only 2 to 3 inches high. It’s a drought-tolerant plant from Europe, where it grows in dry, sandy, and rocky places in the wild. Give it a well-draining location, and it’s practically maintenance-free.
Hardiness zone: 5 to 10
Sun exposure: Full sun to part shade
Height: 2 to 3 inches
Foot traffic: Light
6. White Stonecrop (Sedum album ‘Murale’)
A dwarf cultivar of white stonecrop, ‘Murale’ is a low-grower that tops out at 2 to 3 inches in height.
Growing in clumps, it’s a consummate creeper with fleshy, oblong leaves that spiral up the stem. It roots wherever stem nodes touch the ground, and – like most succulents – will propagate itself from detached leaves.
The foliage is bright green during the summer months and turns fiery orange to deep red in autumn. In mid-summer, pretty white flowers arise on clusters above the foliage on reddish stems. The blooms are especially attractive to butterflies.
As a succulent, Murale is heat and drought tolerant and prefers well-draining sandy soils with low levels of fertility.
Hardiness zone: 3 to 9
Sun exposure: Full sun
Height: 2 to 3 inches
Foot traffic: Moderate
7. Corsican Mint (Mentha requienii)
Corsican mint is a miniature herb that grows low but spreads wide.
Practically flat, it reaches a maximum height of 1 inch. It bears small, rounded green leaves on thin stems that root as they grow, spreading out as much as 2 feet.
From June to August, tiny lilac-colored flowers bloom – so small that they are easily missed.
Similar to other Mentha varietals, Corsican mint will perform best in rich, moist, well-draining soils. Since it’s not drought-tolerant, consider planting it in a spot with afternoon shade.
When Corsican mint’s leaves are bruised or crushed by footfalls, it releases a delicious minty-sage fragrance. The foliage is edible as well, traditionally used as a flavoring for crème-de-menthe, teas, and salads.
Hardiness zone: 6 to 9
Sun exposure: Full sun to part shade
Height: 0.5 to 1 inch
Foot traffic: Light
8. Creeping Mazus (Mazus reptans)
Creeping mazus is a robust little ground cover that puts up with a fair bit of abuse by foot. Along with resilience, it’s a comely plant that grows bright green, narrow, slightly toothy leaves up to an inch long.
A dense matting spreader, creeping mazus tops out at 2 inches high. From late spring to early summer, it supports pollinators with small 2-lipped flowers. These are purplish blue with eye-catching markings in yellow and white.
In its native Himalayan range, creeping mazus thrives in damp meadows and the edges of streams and rivers. In the home garden, it will grow best situated in similarly wet and moist milieus.
Hardiness zone: 5 to 8
Sun exposure: Full sun to part shade
Height: 2 inches
Foot traffic: Moderate
9. Brass Buttons (Leptinella squalida)
Beloved for its finely textured foliage, brass buttons has delicately dissected leaves that resemble tiny fern fronds. Massed together, they form a lush and thick carpet about 0.5 to 2 inches high.
Brass buttons provides a splendid contrast against other leafy shapes in the landscape. The foliage is mainly green with purple, gray and black streaks, turning a reddish hue in autumn. The plant is evergreen in mild climates. Where winters are harsh, it will die back to the ground but will return in spring.
Although the flowers are its namesake, brass button blooms are small and inconspicuous – round like buttons and yellow-green in color. These arrive in late spring and are followed by teeny fruits.
As far as steppable ground covers go, brass buttons is fairly robust to higher levels of foot traffic. In its native New Zealand, it is often used as a lawn and turf substitute.
Hardiness zone: 4 to 10
Sun exposure: Full sun to part shade
Height: 0.5 to 2 inches
Foot traffic: Moderate
10. Mosses, Liverworts, and Hornworts
Nature will throw a ton of unkempt and undesirable weeds our way – but not always. We can sometimes get the perfect plant to grow between pavers by doing absolutely nothing.
The Embryophyte clade, consisting of mosses, liverworts, and hornworts, are low-growing plants with a dense and creeping habit. And they are extremely tough and highly treadable.
Ubiquitous in moist and shaded habitats all over the world, there is likely a native Embryophyte growing nearby on soil, rocks, trees, or fallen logs. As non-vascular plants, they lack true leaves, stems, roots, and flowers and draw in moisture and nutrients through their leaf-like surfaces.
They are pioneer plants, first to arrive and restore barren lands. These intriguing and odd-looking greens are valuable for building soil by cycling nutrients and providing a habitat for insects and microorganisms.
Feather Mosses (Rhynchostegium spp.)create soft and pillowy cushions between the narrowest of gaps. It reproduces with reddish beaked capsules that arise gracefully above the greenery.
Liverworts (Marchantiophyta spp.) have flat, overlapping, irregularly shaped leaves. Some species reproduce asexually via small cup-like structures on the leaf surface. Others, like common liverwort, have separate male and female reproductive organs; flat discs produce sperm while starry-topped stalks contain the ova.
Hornworts (Anthocerotophyta spp.) are similar in appearance to liverworts, but have flattened ribbon-like leaves that fork into a Y or horned shape.
If you luck into having an Embryophyte already colonizing your stonework, leave them where they are and enjoy some zero-maintenance ground cover. If not, these plants can be transplanted by carefully removing a sample from the parent plant and gently tucking them into stone crevices.
Tips for Growing Plants Between Pavers
Prep the gaps: Stepping stones, flagstone patios, and paver blocks are usually sitting atop compacted soil and several inches of sand. Make the space more hospitable to plant life by digging out a few inches of soil between the stones. Replace it with rich compost to give your ground-huggers an excellent start.
Space plants 6 to 9 inches apart: You can direct seed, start seeds indoors, or purchase flats to get your ground covers started. Set them a ways apart, and you’ll save time and money by letting the creepers do most of the filling in.
Let plants get established: Newly planted ground covers are fragile at first. Avoid stepping on them for at least a few weeks so they can grow freely and establish their roots.
Give plants consistent moisture: The trick to getting plants established is water, and steppables are no exception. For the first few weeks, check in on plants every day and give them a drink when they need it. Use a spray bottle or mister to moisten the more delicate specimens.
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