Groundcovers are low-growing plants that spread quickly to form a dense cover. They add beauty to the landscape, and they can also solve many planting problems in difficult sites. Groundcovers are also excellent choices where turfgrass is not desirable or practical. Choosing the right groundcover for a landscape is important as they often consume large areas.
Why use groundcovers in sunny sites
Some groundcover plants prefer shade. Others thrive in full sun. Some prefer moist soil, while others need dry or well-drained soil. To work well as groundcovers, plants have to be tough, durable, and relatively fast growing but not invasive. Compared with plain mulch or high-maintenance turf, these groundcovers are built for long term success in Zone 6.
Site factors for full sun groundcovers
- Full sun and hot slopes - South or west facing banks dry out quickly and bake in summer.
- Well-drained soils are essential for many sun-loving groundcovers; Delosperma and many Sedum demand excellent drainage, especially in winter.
- Well-drained to dry soils suit plants such as Thyme, Snow-in-summer, and many stonecrops.
- Some species perform best in average garden beds in sun to part shade and tolerate a wider range of conditions.
Characteristics of good low-maintenance, sun-loving groundcovers
Some groundcovers require less sunlight and less moisture and nutrients than grass. Some groundcovers are improved by occasional shearing. Because groundcovers live for many years in the same spot, it is worth the effort to prepare the soil well before you plant them. Improper soil preparation is a frequent cause of groundcover failures. The soil should be worked to a depth of 8 to 10 inches.
Planting, spacing and establishment
Selection of a suitable plant for groundcover depends on the area where it will be grown. Space the plants according to their size, the immediate effect desired, and their rate of growth and habit. If the individual plants are spaced too far apart, weeding can be a problem and the time required for complete coverage can be quite long. On the other extreme, planting too closely together can be a needless waste of time, money and plant materials. Usually, it is best to space the plants so the groundcover areas will, for the most part, be completely covered by the end of the third growing season.
Most groundcovers can be planted at any time of the year. However, fall planting takes advantage of lower temperatures and natural rainfall. Watering is reduced and plants establish a stronger root system before summer. Water requirements vary with different plants. Water deeply the first season - Aim for consistent moisture until plants have rooted into surrounding soil. A soil test provides the best guidance for fertilizer usage. In the absence of a soil test, incorporate a complete fertilizer, such as 10-10-10.
It may take up to two years to establish a groundcover area. Fertilizing and watering will probably be required during this period. Apply fertilizer based on how fast you want full coverage to occur. Begin fertilizing 4 to 6 weeks after planting, then make one application in the spring, another during summer, and a third in September. If rapid coverage is desired, make a fourth application during the summer months. A complete fertilizer such as 12-4-8 or 16-4-8 or a similar analysis applied at the rate of 1 pound of nitrogen per 1000 square feet is adequate.
Maintenance tips
Weed control is a must until the groundcover is fully established. A 2-inch layer of mulch will help in the control of weeds. Some groundcovers are improved by occasional shearing. Wintercreeper can be clipped at a 4- to 6-inch height. Others, such as dwarf mondograss, can be clipped with hedge shears or mown when they appear shabby. Remove the old growth of mondograss because the leaves harbor fungi, which can disfigure and kill newly emerging leaves. To rejuvenate pachysandra and other herbaceous evergreen groundcovers that have suffered winter burn, use a rotary mower on its highest setting. Early spring is usually the best time to prune groundcovers because new growth will quickly cover the bare stubs.
Pest and disease considerations
Several fungi and bacteria may cause leaf spots. Infected leaves can be picked off and discarded. Root, stem and crown rots are fungal diseases that are more serious in poorly drained soils. Some groundcover plants, such as ajuga, are very susceptible to root-knot nematodes. Nematodes are microscopic worms that live in the soil and feed on plant roots.
Avoiding invasive problems
Choose plants that are known to do well in the conditions found in your landscape and most importantly guard against plants known to become invasive. English ivy (Hedera helix) and large leaf periwinkle (Vinca major) are considered invasive in many Zone 6 regions and can escape into woodlands. Fast spreaders like Ajuga reptans, Lamium maculatum, Lysimachia nummularia ‘Aurea’, Viola sororia, Mazus reptans, and Sagina subulata can blanket an area quickly. Use them where you want fast coverage or where beds are naturally contained by paths, walls, or edging. Vining groundcovers should not be allowed to consume trees since they can choke out sunlight and weigh down branches.
Top low-maintenance groundcovers suited to full sun
Several species of Thyme (Thymus spp.) make wonderful, fragrant groundcovers for full to part sun. Grow in well-drained to dry soils as plants will not tolerate wet conditions, especially over the winter months. Most species grow 3 to 6 inches high and spread to 2 feet. Small pink flowers bloom in spring to early summer.
Stonecrops (Sedum spp.) are succulents with fleshy leaves and small, star-shaped flowers. Low-growing types between 2 and 8 inches tall are excellent groundcovers. Flower colors include white, pink, red, and yellow. Stonecrops are easy-to-grow, long-lived perennials. However, they do require well-drained soils. Best growth occurs in full sun.
Delosperma is an excellent option for rock gardens, parking strips, rock walls - evergreen, drought tolerant, low maintenance, and deer resistant. Top drought tolerant groundcovers for Zone 6 include Sedum spurium, Delosperma cooperi, and Thymus serpyllum.
Moss phlox (Phlox subulata) forms dense, carpet-like mats. Plants are 4 to 6 inches tall. Flower colors include white, pink, red, blue, or purple. Moss phlox is easy to grow. It performs best in sunny areas and well-drained soils.
Snow-in-summer (Cerastium tomentosum) produces a blanket of white flowers in early summer. Grow in full to part sun. Well-drained to dry soils are essential as this groundcover will not tolerate wet conditions. Great for rock gardens.
Thymus serpyllum (Creeping Thyme) - Fragrant, low, and tough. Sedum spurium ‘Dragon’s Blood’ - Fast spreading succulent mat for heat, drought, and lean soil. Liriope muscari - Evergreen or semi-evergreen, drought tolerant, and dependable in sun or shade. One of the most reliable all around groundcovers for Zone 6 is Liriope muscari.
Other sun-tolerant, low-maintenance options
- Moneywort (Lysimachia nummularia) - Suitable for wet sites; 'Aurea' has lime green to yellow foliage but it does spread rapidly and can become invasive.
- Barren strawberry (Waldsteinia fragarioides) - Low-growing, mat-forming; can be grown in partial shade to full sun; well-drained soils are best.
- Candytuft (Iberis sempervirens) - Semi-evergreen, semi-woody; white flowers in spring; grows 6 to 12 inches tall in full sun and moist, well-drained soils.
- Basket-of-Gold (Aurinia saxatilis) - Spreading 6 to 12-inch tall plants; prefers well-drained soils; grows best in full sun.
- Pinks (Dianthus deltoides and D. gratianopolitanus) - Low, mat-forming, blooms for 8 to 10 weeks; perform best in moist, well-drained soils in full sun.
- Leadwort (Ceratostigma plumbaginoides) - 8 to 12 inch tall groundcover with gentian blue flowers in late summer; requires well-drained soil.
- Lamb's ear (Stachys byzantina) - Soft, fuzzy, silver-gray leaves; grow in full sun to part sun in well-drained to dry soils; avoid overwatering.
- Common yarrow (Achillea millefolium) - Spreads by rhizomes; grow in full to part sun and well-drained to dry soils.
Design combinations and placements
Combine Thymus serpyllum, Liriope muscari, Liriope spicata, and low mats of Sedum spurium ‘Dragon’s Blood’ on sunny banks. Thread Lysimachia nummularia ‘Aurea’ around clumps of Brunnera macrophylla, compact Hosta cultivars, glossy Mitchella repens, and rich toned Ajuga reptans. Combine Epimedium x rubrum, Asarum canadense, and Pachysandra procumbens, then edge with clumps of Carex pensylvanica.
Practical spacing and timing tips
Zone 6 offers a generous spring and fall planting window. Space according to spread rate - Fast spreaders 12 to 18 inches apart, slower or clumping types 8 to 12 inches apart. Most groundcovers in Zone 6 take one to two growing seasons to fill in. Plant fast spreading groundcovers 12 to 18 inches apart and slower, clumping types 8 to 12 inches apart.
Keep in mind, however, that some may spread too aggressively in certain garden settings. All of these low-growing, creeping plants spread readily in the garden - that is why they are good groundcovers! Keep in mind, however, that some may spread too aggressively in certain garden settings. There are also several species of groundcovers for shady sites. Some of the shade-loving species, such as bugleweed and vinca, perform equally as well in both shady and sunny sites.
Quick reference table - common sun-loving low-maintenance groundcovers
| Plant | Height | Soil | Notes |
|---|---|---|---|
| Thymus spp. (Thyme) | 3-6 in | Well-drained to dry | Fragrant, tolerates light foot traffic |
| Sedum spp. (Stonecrop) | 2-8 in | Well-drained | Drought-tolerant, colorful foliage |
| Phlox subulata (Moss phlox) | 4-6 in | Well-drained | Spring carpet of color |
| Delosperma | Low mats | Excellent drainage | Rock gardens, drought-tolerant |
| Cerastium tomentosum (Snow-in-summer) | 6-12 in | Well-drained to dry | Silvery foliage, white flowers |
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Groundcovers are also excellent solutions for erosion control on steep banks or slopes. Some can be used on steep banks to help control erosion. Creeping Buttercup can become a troublesome lawn weed as it tolerates mowing. Use caution with plants that thrive in the site conditions and guard against those that may escape into natural areas.