If you’ve ever seen a determined dandelion growing out of the crack in a sidewalk, you understand the idea behind growing herbs in tight spaces. If an unwanted plant appears to be growing out of nowhere, then a more desirable selection will probably grow there as well.
Some hardy herbs will grow almost anywhere there is soil, sun and a water source. With a little encouragement, fibrous-rooted herbs can provide fragrant weed control along walkways or the difficult-to-maintain areas between stone pavers. Little herbal gems tucked into stone crevices can define a stone pathway, lure walkers down rocky steps or highlight an unusual hardscape feature in a garden. Discover the ways to take advantage of these tight spaces.
Between a Rock
Brushing against a retaining wall planted with herbs or stepping on low-growing herbs planted between a wall and the stepping stones releases their scents. Do not overplant these miniature rock gardens if moisture and soil between the stones is limited.
Drainage from the stones and the shade can provide a moist ground in front of retaining walls. Shady, moist ground is ideal for mints. Give the Mentha genus a try in a confined space that will control the wide-spreading underground rhizomes. The best-known species are peppermint (Mentha ×piperita) and spearmint (M. spicata). Other fragrant citrus-mint choices, such as lime, orange and lemon mint, will grow in the same conditions as peppermint and spearmint. Pennyroyal (M. pulegium) is a mint family member ideal for the confined spaces between rock walls and sidewalks.
Herbs planted in the crevices of a wall can dry out quickly. Before planting in a retaining wall, observe how much sun or shade the plants will receive. Unless the wall is facing directly south, plants that thrive in shade or partial shade are best. Consider that plants on a southern exposure must adapt not only to the limited space but also to the heat of sun-warmed stone.
A south-facing wall, or any sunny place with well-drained soil, is a good location to plant lavender. Mix in a handful of leaf mulch or other organic fertilizer to the planting hole. A well-mulched lavender plant does not need much additional water in the summer. Once established, lavender is tolerant of dry soil. Try several varieties of lavender to extend your bloom season and quickly discover which varieties do best in your location. Deer and rabbits do not care for this fragrant plant, but it can’t tolerate much foot traffic.
Walk This Way
Pavers tend to protect the soil from erosion and retain moisture for the herbs while the herbs provide weed control between the pavers. Protect newly planted areas from heavy traffic and provide shade and adequate water, especially during the first growing season as the plants work to establish themselves. Be patient with this project, choosing to underplant rather than overplant herbs. Though the tiny herbs look sparse, frugal planting now will save work in the long run with less thinning and trimming overgrown pathways. While no plant is maintenance-free, the restricted growth area between pavers and foot traffic will tend to “prune” most plants.
Once established, some herbs planted between stepping stones can withstand occasional garden foot traffic without significant damage. Among the most suitable for this purpose are the low-growing thymes, which have tiny fibrous roots that adapt quickly to rock gardens and walkways. Common thyme (Thymus vulgaris) is a good first choice.
An Old World Mediterranean member of the Labiatae, common thyme is also known as English thyme, garden thyme and mother-of-thyme. The sun-loving thymes are an ideal groundcover and are great for rock gardens. Stepping on the thymes compresses the foliage, releasing the oils from the leaf bottoms and creating a wonderful scent in the garden. Low-growing creeping thyme can accent seating space. Call attention to these tiniest of flowers by planting creepers near a rest area or under a garden bench.
Creeping pink thyme (T. praecox) is a low-growing semi-evergreen with pretty, little pink flowers that last most of the summer. The fast-growing creeper is well suited to the confines between stepping-stones, filling in between stones quickly with tiny complementary gray-green leaves. It is delightful in the pathways of butterfly gardens.
“Pavers tend to provide the slightly alkaline soil that herbs need,” Rose Marie Nichols-McGee of Nichols Garden Nursery says. “In the spring, just lift pavers and pop herbs in. This really is a project for spring so new plants have the best chance to establish before they begin to struggle in the heat of summer. Or plant violet seed in the fall and winter. You can sprinkle the violet seed between pavers.”
Sweet violet (Viola odorata) does best with a fall or winter sowing, as the seed benefits from the cold. Violet seed is slow to germinate and will cheerfully appear between the pavers in the spring with small but mighty purple blooms.
Nichols-McGee likes to group similar varieties of any plant together for a well-designed look. Planting similar varieties so they grow at the same rate and bloom at the same time is attractive. For example, a row of pavers in ‘Lemon Frost’ thyme (T. ×citriodorus ‘Lemon Frost’), next to a paver row of creeping red thyme (T. serpyllum), followed by a stretch of lime thyme (T. serpyllum) will result in tiny waves of color and consistent growth rates as the plants mature.
For stepping stones in shade, Corsican mint (M. requienii), is very aromatic and grows only 1 or 2 inches high. Nichols-McGee suggests this mint for moist, shaded areas. Because of its carpet-like growth requiring very good drainage and plenty of shade, Corsican mint is suitable for planting between well-shaded pavers, raised beds or in quick-draining containers.
Rarely flowering, creeping golden marjoram (Origanum vulgare ‘Aureum’) makes a tough but attractive groundcover or is a good choice between stepping stones. This herb can be mowed or trimmed with pruners to keep it flat.
Another hardy choice is a shortened variety of Roman chamomile. Lawn chamomile (Chamaemelum nobile ‘Treneague’) is a perennial that grows no more than 6 inches tall. It is a nonflowering herb often recommended for lawns and groundcovers. The apple-scented chamomile forms a compact mat, useful as a pathway. It is a good spacer between pavers in full sun and well-drained soil.
Another Brick in the Wall
The purpose of a retaining wall is to hold back the soil behind the wall. If you have the opportunity to build a retaining wall, build in little garden ledges or recesses in the wall as you lay the stone courses. Plants will accent your beautiful stonework and tie the wall into the landscape. Pay attention to placement when using cascading plants on top of the wall so they cover some stones and draw attention to other more interesting stones.
Leave small separations between a few stones randomly spaced in the wall. Limit the number and size of planting spaces in the wall to maintain its strength and natural beauty. To prevent soil or gravel erosion when plants are absent, don’t leave large, obvious gaps in the wall.
Separations between stones should create a soil trail that goes all the way through to the back fill behind the wall, so consider slightly tilting the stones backward to direct the rainwater back rather than washing soil out the front of the wall. Fill the space between the rocks with a rich organic soil.
Build the wall several inches out in front of the soil it is supposed to hold. Backfill retaining walls with gravel to help with drainage, especially in cold climates where frost heaving can impact soil against the wall. After the retaining wall is firmly in place, it is time to plant your garden wall.
Push plants into the tunnels 2 or 3 inches deep, adding soil as needed to cover the roots and firm the crown of the plant securely inside the wall.
Devote time and attention to your new plants in the retaining wall. Provide protection from harsh winds and sun until the plants are established. Make sure the starter plants are getting plenty of water until plants are well rooted. The stone wall and the gravel backfill will drain quickly making it necessary to water plants often, especially during the first growing season.
Stone paths and walls are meant to last for years, so don’t be in a hurry to complete this garden project; too many new plants will suffer from the competition for the limited nutrients and water and they may eventually become overgrown and require cutting back.
Planting in the nooks and crannies in your yard can add whimsy and fun to your existing garden spaces. Between the cracks may just be the hard-to-find space you need to add dainty, fragrant herbs to your garden.
In a Pinch
Rose Marie Nichols-McGee has this money-saving tip for herb growers tackling a large stone paving project or long pathway.
Many of the hardy herbs that are suitable for pathways can easily be divided as soon as you pop them out of their containers. When planning how many plants to purchase, considered dividing healthy starter plants even before the first planting.
For example, loosen a 4-inch container-grown starter plant from the pot. With a clean, sharp knife cut the plant into two or three smaller plants, making sure each division has enough root system to get off to a good start.
Newly divided herb plants can save money, but will take time to recover from surgery. This is a project best suited to the milder weather of springtime. Nurture these tiny plants, giving them extra protection and adequate water to become well established before the heat of summer. Use plenty of organic matter in the planting soil and generously mulch your new arrivals.
Patsy Bell Hobson is a freelance writer and Master Gardener who is always searching for new garden spaces at her home in Cape Girardeau, Missouri.