Ground Covering Plants

Ajuga or Bugleweed (Ajuga reptans)

Ajuga is a fast-spreading ground cover requiring sun to light shade and moist soil. It grows 10 cm high, and develops flowers spikes, which are 20cm tall in late spring. The flowers are often deep blue though some cultivars are white or red. Shiny rosettes of leaves, either bronze-coloured or variegated grow from a horizontal stem. The cultivar ''Braunherz ajuga' is especially resistant to insect attacks. Though it is hardy to zone 4 it dies out during particularly cold winters in Ottawa.

Bugleweed

Cotoneaster (Contoneaster dammeri)

A low-growing, evergreen shrub that reaches 25 -45cm (1-1 1/2') in height and can spread more than 2m (6') because branches in contact with the soil root freely. This plant has small, glossy leaves with small white flowers that emerge in late spring, followed by red berries. Will thrive in full sun to partial shade, in well-drained soils. Ideal for slopes.

Cotoneaster

Japanese Spurge (Pachysandra terminalis)

Japanese spurge forms a neat, uniform, evergreen groundcover. This plant grows best in light to full shade and moist,well-drained soils with a pH range of 5.5 to 6.5. It grows 15-20 cm (6-8") high and some cultivars have variegated leaves.

Japanese Spurge

Periwinkle (Vinca minor)

Periwinkle grows in full sun to deep shade, reaching 15 cm (6") high with shiny evergreen leaves. Periwinkle blooms in spring, most have lilac-blue flowers, but there are white or violet-pink cultivars available. This plant can withstand droughts once established. Periwinkle spreads rapidly and can crowd out other plants.

Creeping Thyme (Thymus vulgaris or T. serphyllum)

This is a good ground cover for full sun, loose, well-drained soil. There are many cultivars available, all with scented leaves, ranging from glossy green to variegated or wooly. In early June the 7-15 cm (3-6") tall mat is covered in tiny purple flowers. It spreads because the stems root in the soil they come in contact with. It dies out during winters with little snow cover. It is used as a ground cover, rock garden plant or between stepping-stones in a walk.

Thymus serphyllum

Creeping Juniper (Juniperus horizontalis)

This juniper grows slowly, but is excellent for covering rocky slopes. It requires full sun, well-drained soil and good air circulation. In fact it is tolerant of heavy alkaline soils also. 'Blue Acres', 'Blue Chip' and 'Wiltonii' have bluish foliage and very low growing. 'Green Acres' is a green cultivar. 'Plumosa' and 'Plumosa Compacta' are very popular junipers, commonly refered to as Andorra or dwarf Andorra, they turn a purplish colour after the first frost.

Juniperus horizontalis cultivar

Bigfoot Geranium (Geranium macrorrhizum)

The plant has deeply lobed leaves forming a mounding plant 20-30 cm (8-12") tall with flower stalks in early summer bearing white, pink or magenta flowers (cultivar dependant). Due to the intense heat in summer in Ottawa, it should be grown in partial shade. Plant in moist organic/humus rich well drained soil. They tolerate alkaline soils.

Geranium macrorrhizum

Bloodred Geranium (Geranium sanguineum)

The pubescent lobed leaves are less than 5 cm (2") across and turn maroon after the first frost. Flower stalks rise out of the mounding plant, which is 30 cm (12") tall by 60 cm (24") wide, bearing magenta, rose or white flowers depending on the cultivar. It tolerates hot sunny spots in Ottawa. Plant it in rich, well-drained, moist soil.

Note: There are many more species and cultivars of Geraniums that make superb ground covers.

Geranium sanguineun

Clover (Trifolium repens)

White Dutch clover is an early summer blooming, low broadleaf plant 7-8 cm (3") that is used in lawns. Until the 1980's it was included in grass seed mixes. Clover fixes Nitrogen enhancing grass growth. It needs no mowing, though tolerates it, and withstands traffic. Clover has deep roots so it is drought tolerant. Cloverleaves die with frost leaving the soil exposed in the early spring and fall (coincidentally when grass grows vigorously), for this reason clover cannot be grown alone for erosion control. Clover spreads easily.

Clover
 

Crown Vetch (Coronilla varia)

This ground cover is ideal for large sunny banks that are too dry for grass. It forms an intertwined mass up to 30 cm thick. Like clover it is deciduous so does not cover the soil from late fall to early spring.

Crown Vetch

Dwarf Chinese Astilbe (Astilbe chinensis 'Pumila')

Low growing dark green, fine textured leaves grow from a stoloniferous root system. In mid summer it has 35cm (14") mauve-pink fluffy blooms. It spreads quickly if grown in partial shade and moist well-drained soil.

Goutweed Bishop's weed (Ægopodium podagraria)

Goutweed grows in sun or shade and spreads extremely rapidly (invasively) the rhizomatic root system thrives in any soil type. It has green or variegated cream and green leaves and grows 25 cm (10") high. Use as a ground cover where it is restricted by buildings and concrete walkways.

Lily-of-the-Valley (Convallaria majalis)

Grows about 15-30 cm (6-12") high with vertical pointed green leaves about 2.5-8 cm (1-3") wide, It has fragrant white flowers in May. Lily-of-the-valley grows in partial shade to deep shade. This plant is a vigorous spreader and if left unchecked may suppress other plants. Control its spread by digging out plants. It disintegrates in the heat of Ottawa summers if it is growing in dry soil. The bright red berries produced in summer are poisonous.

Convallaria majalis

Bishop's Cap or Barrenwort (Epimidium ssp.)

Crimson, pink, yellow, or white flowers rise over a 30 cm (12") mounding plant in mid spring. Plant in moist, ordinary soil, 30 cm (12") apart as they increase slowly. They are excellent for the deep shade under trees where few other plants thrive. The foliage is semi evergreen and emerge from the winter red tinged.

Creeping Jenny or Moneywort (Lysimachia nummularia)

This ground hugging plant blooms yellow flowers profusely in late spring. It thrives in sun or shade so long as the soil is moist. It is invasive making it ideal for slopes.

European Wild Ginger (Asarum europeaum)

This plant spreads to about 25cm (10") and has glossy kidney shaped leaves on 12cm (5") stems. They are ideally suited for acidic soil with a pH range of 5.5 to 6.5 growing in humus rich moist soil in shady spots.

Spotted Deadnettle or Lamium (Lamium maculatum)

Some common cultivars of Lamium include 'White Nancy' and 'Beacon Silver'. It has variegated leaves and is best in partial to full shade, and ordinary garden soil. Flower colours are white, pink and mauve-pink. It grows to approximately 20-30 cm (8-12") tall and spreads easily.

Lamium maculatum

Moss phlox (Phlox subulata)

Forms a moss-like mat 15 cm (6") deep; with white, blue, pale pink or dark pink flowers in spring. It needs full sun; and well-drained soil, even tolerating alkaline soils. After it blooms cut the stems back half way to promote new growth in the center and reblooming.

Daylilies (Hemerocallis spp.)

Daylilies are hardy, grass-like plants that are available as dwarfs 30 cm (12") to tall cultivars 1.3 m (4') and in many colours. They grow well in well-drained, ordinary garden soil. Yellow and orange cultivars flower best in full sun, whereas pastel coloured plants should be placed in partial shade otherwise the blooms fade.

False Rockcress (Aubretia deltoidea)

This is a greyish green, spreading plant. Thrives in full sun in well-drained ordinary garden soils. In early spring rock cress is covered in 15cm high rose-lilac to purple blossoms that fade to pink/purple. After it blooms trim back the stems to maintain it as a dense 25cm (12") wide mat.

Foamflower (Tiarella cordifolia)

This ground cover grows 15-30 cm (6-12") tall in medium to heavy shade and rich moist soil. It produces white flower spikes in the spring.

Hostas (Hosta spp.)

Thrives in rich, moist soil in the partial to full shade, in cool yards the gren and variegated cultivars grow well in full sun if the soil is moist or mulched. The leaves range in shape from narrow to broad, and come in many shades and patterns from deep blue-green to gold, plain or variegated. Hosta cultivars bloom from summer to fall having white or lilac fine lily-like flowers on spikes.

Hosta Cultivars

Moss

Moss lawns are becoming popular. They stand up to some traffic and certainly need no mowing. Moss grows in shady soil, that is acidic, poorly drained and has low fertility. Grass likes well-drained, fertile soil with a pH of 6.5 (near neutral). Choose which you would like, then adjust the soil pH accordingly. To get rid of moss, increase the light, dig in lime, and seed, or plant with another ground cover.

Rock Cress or Arabis (Arabis caucasica)

This is a greyish green, speading plant. Thrives in full sun to partial shade in well-drained soils. In early spring rock cress is covered in 15cm high white blossoms that fade to pink/purple. After it blooms trim back the stems to maintain it as a dense 25cm (12") wide mat.

Snow-in-Summer (Cerastium tomentosa)

White flowers cover the grey leafed mat in late spring. The plant grows to 15 cm (6") tall by 1m (3'). It thrives in well-drained soil with low fertility in full sun. Cut back the foliage after it blooms to promote a dense compact plant.

Stonecrop (Sedum spp.)

Stonecrop can thrive in poor to rich soils and tolerates both sun and shade conditions. Yellow or red star-shaped flowers appear in the summer. Sedum acre is a low-growing, light-green succulent plant that spreads quickly. Should the plant become a nuisance, it is easy to weed.

Sedum stonecrop

Sweet Woodruff (Galium odoratum)

This 15 cm (6") tall ground cover is best in moist shady spots where grass won't grow. It has whorled green foliage and tiny white flowers in late spring. The leaves and stems have a pleasant scent when cut or crushed.