A properly constructed rock garden, with rocks and soil elevated in tiers provides good drainage for many small plants that might otherwise succumb to winter and spring wetness.
Rocks are best situated where the plants will receive maximum sunshine and not be shaded by trees.
In addition to perennials and small spring flowering bulbs such as crocus, snowdrop and winter cconite, using dwarf evergreen enhances and maintains year-round interest in any rock garden. Many varieties of dwarf spruce, yew and hemlock are very suitable and widely available.
The perennials in this list are mostly under 30 cm.
Common Name and Botanical Name
Wooly yarrow, Achillea
Lebanon or Persian cress, Aethionema
Bugle flower, Ajuga (many varieties)
Lady's mantle, Alchemilla
Ornamental onion, Allium moly and others
Basket of gold, Alyssum
Pearly everlasting, Anaphalis
Rock Jasmine, Androsace
Pussy toes, Antennaria
Dwarf columbine, Aquilegia
Rock cress, Arabis
Silver mound, Artemisia
Silver brocade, Artemisia
Alpine aster, Aster
Dwarf astilbe, Astilbe
Purple rock cress, Aubretia
English daisy, Bellis
Carpathian harebell, Campanula
Dalmation bellflower, Campanula (there are many other small Campanula)
Silver thistle, Carlina
Dwarf coreopsis, Coreopsis
Dianthus/pinks, Dianthus (many named varieties available)
Dwarf columbine, Dicentra eximia
Cushion spurge, Euphorbia
Indian strawberry, Fragaria
Yellow bedstraw, Galium
Creeping baby's breath, Gypsophila
Rock rose/sun rose, Helianthemum
Coral bells, Heuchera
St. John's wort (Dwarf), Hypericum
Hardy gloxinia, Incarvillea
Dead nettle, Lamium
Golden flax, Linum flavum
Prickly pear, Opuntia
Dwarf beardstongue, Penstemon
Perennial potentilla, Potentilla
Rock soapwort, Saponaria
Dwarf blanket flower, Gaillardia
True geranium, Geranium
Hosta, Hosta (sun tolerant varieties)
Candy tuft, Iberis
Dwarf iris, Iris pumila
Dwarf feverfew, Matricaria
Evening primrose, Oenothera
Iceland poppy, Papaver
Creeping phlox, Phlox
Pasque flower, Pulsatilla
Gold moss, Sagina
Sedum is a very important rock garden family. Dozens of varieties are readily available and hundreds are possible. All sedum varieties flower in their season from early summer to late fall. Flower colours vary from pink, red, white or yellow. More important than their flowers, however, is their interesting and colourful foliage. Sedums are a MUST in any rock garden.
Hens and Chickens — Sempervivum
Another important rock garden plant, Sempervivum has fleshy rosettes of foliage with the mother plant surrounded by many small plantlets. These can be detached and planted in another spot.
There are many named varieties, all with interesting colourful leaves.
Moss campion, Silene schafta
Blue-eyed grass, Sisyrinchium
Lamb's ears, Stachys
Many varieties of thyme are available. All are flowering plants but are valued more for their foliage — in shades of green, plus gray, gold and silver.
Many small Veronicas or speedwells are available, including creeping varieties.
Violets — Viola
Many varieties are available in many different colours.
Grasses for rock gardens
The smaller, clump-forming (non-invasive) grasses add great charm and quite a different touch in a rock garden. Recommended — blue fescue varieties, tuberous oat grass, blue oat grass, June grass (Koeleria), plus grass-like plants such as sedges (Carex) and wood rush (Luzula).