The ideal location for a rock Garden is a natural slope or terrace,
such as those found at the side or rear of a house based on a
split-level or Garden-level design.
Use rocks of one geological type. An effective rock Garden should
have several large rocks, some weighing 200 pounds or more.
Set the rock into the ground so at least one-third is buried. Place
rocks in a natural way, following the grain of the rock. Position rocks
to control soil erosion between rocks and to allow soil pockets of
various sizes for plants. Use smaller, similar rock as mulch.
Provide good drainage. Most plants suitable for rock Gardens require
a well-drained soil. For most plants, incorporate organic matter into
heavier clay soils to improve texture and provide better drainage.
A rock Garden should be no larger than can be easily maintained. Rock
Gardens have high maintenance requirements. Weed control is the biggest
problem. Mulch can minimize weeding.
Plant a variety of species, repeating some species several times to
make the Garden look natural. Ideally, rock Garden plants should spread
slowly. Take care not to overplant.
Plant Selection
Many types of plants are suitable for rock Gardens. Generally, plants
that are low growing and have a clumping habit are preferred. Perennial
plants are most common in rock Gardens, although some annuals can be
used.
|
Table 1: Recommended rock Garden
plants.
|
|
Plant Name
|
Height
|
Exposure
|
Soil
Preference
|
Flower
Color
|
Bloom
Period
|
Remarks
|
|
Ajuga reptans
Carpet bugle
|
4-10
in.
|
Shady
spots
|
Well-drained
|
Blue,
pink,white, purple
|
May-June
|
Several varieties.
|
|
Alyssum montanum
Mountain alyssum
|
4-8
in.
|
Sun
|
Dry,
rocky
|
Yellow
|
April-May
|
Gray foliage.
|
|
Arabis alpina
Alpine rockcress
|
6
in.
|
Sun
|
Dry,
rocky,
poor
|
White,
pink
|
April-May
|
Evergreen; mat-like foliage.
|
|
Arabis caucasica
Wall rockcress
|
6-12
in.
|
Sun
|
Well-drained
|
White
|
April-May
|
Many varieties.
|
|
Armeria maritima
Thrift
|
4-10
in.
|
Sun
|
Dry,
well-drained
|
Pink,
white,
purple
|
May-June
|
Several varieties.
|
|
Aurinia saxatilis
Basket-of-gold
|
8-12
in.
|
Sun
|
Dry,
rocky
|
Yellow
|
April-May
|
Shear after bloom.
|
|
Campanula carpatica
Carpathian harebell
|
8
in.
|
Sun
|
Well-drained
|
White,
blue,
purple
|
June-July
|
Several varieties.
|
|
Campanula elatines
Adriatic bellflower
|
6-8
in.
|
Sun
to
part shade
|
Well-drained
|
Blue-violet
|
May-June
|
Sharp-toothed foliage.
|
|
Campanula rotundifolia
Bluebell
|
8-12
in.
|
Part
shade
|
Well-drained
|
Blue
|
May-Sept.
|
Bell-like flowers on slender stems.
|
|
Cerastium tomentosum
Snow-in-summer
|
4-10
in.
|
Sun
|
Dry,
well-drained
|
White
|
May-June
|
Aggressive; shear after bloom.
|
|
Delosperma cooperi Purple ice plant
|
2-3
in.
|
Sun
|
Well-drained
|
Purple
|
June-frost
|
Succulent foliage.
|
|
Dianthus deltoides
'Brilliant',
'Zing Rose'
|
6-8
in.
|
Sun
to
part shade
|
Well-drained
|
Red
|
May-Sept.
|
Foliage dark green; matted.
|
|
Dianthus gratianopolitanus
'Tiny Rubies',
'Bath's Pink'
|
4-10
in.
|
Sun
|
Well-drained
|
Pink
|
May-June
|
Spreading; grayish-green foliage.
|
|
*Euphorbia polychroma
Cushion spurge
|
12-18
in.
|
Sun
|
Well-drained
|
Yellow
|
May-June
|
Red fall color.
|
|
Geranium spp.
Cranesbill
|
Varies
with
species
|
Sun
to
part shade
|
Well-drained
|
White,
pink,
red, purple
|
May-Aug.
|
Several species suitable for rock and amended
Gardens.
|
|
Gypsophila repens
Creeping baby's breath
|
4-8
in.
|
Sun
|
Well-drained
|
White,
pink
|
June-July
|
Mat-like.
|
|
Heuchera sanguinea
Coral bells
|
6-18
in.
|
Sun
to
part shade
|
Well-drained
|
Red,
pink, white
|
June-Aug.
|
Mounded foliage with taller bell-shaped
flowers.
|
|
Iberis sempervirens
Candytuft
|
12
in.
|
Shade
to
part sun
|
Well-amended
|
White
|
May-June,
repeats in fall
|
Evergreen foliage.
|
|
Linum flavum 'Compactum'
Dwarf golden flax
|
6-12
in.
|
Sun
|
Well-drained
|
Yellow
|
May-July
|
Darker green foliage.
|
|
Oenothera speciosa
White evening primrose
|
6-10
in.
|
Sun
|
Well-drained
|
Pink
to white
|
June-Sept.
|
Day-flowering.
|
|
Penstemon caespitosus
Creeping penstemon
|
3-6
in.
|
Sun
|
Well-drained
|
Blue
|
May-June
|
Mat-like; dark green foliage.
|
|
Phlox subulata
Moss pink or creeping phlox
|
6-8
in.
|
Sun
|
Well-drained
|
Pink,
white,
lavender
|
April-May
|
Several varieties.
|
|
Potentilla nepalensis
'Wilmottiae'
Wilmott cinquefoil
|
6-12
in.
|
Sun
|
Well-drained
|
Pink
to red
|
May-July
|
Best planted in groups.
|
|
Saponaria ocymoides
Rock soapwort
|
6-10
in.
|
Sun
|
Well-drained
|
Pink
|
May-July
|
Shear after bloom.
|
|
Saxifraga spp.
Saxifrage
|
Varies
with
species
|
Sun
to
part shade
|
Moist
but
well-drained
|
Varies
with species
|
April-July
|
Many species.
|
|
Sempervivum spp.
Houseleek,
hen and chicks
|
2-6
in.,
flower taller
|
Sun
|
Dry,
gravelly
|
Unimportant
|
July-Sept.
|
Succulent, evergreen foliage in rosettes.
|
|
Thymus pseudolanuginosus
Woolly thyme
|
2-4
in.
|
Sun
|
Loose,
well-drained
|
Infrequent,
pink and purple
|
June-July
|
Woolly-gray foliage turns purplish in winter;
groundcover.
|
|
Thymus serpyllum
Mother-of-thyme
|
1-4
in.
|
Sun
|
Loose,
well-drained
|
Purple
|
June-July
|
Aromatic foliage; mat-forming groundcover.
|
|
Veronica pectinata
Woolly veronica
|
2-3
in.
|
Sun
to
part shade
|
Well-drained,
fertile
|
Blue
to purple
|
May-July
|
Gray, mat-like foliage turns purplish in
winter.
|
|
Veronica prostrata
Prostrate speedwell
|
2-6
in.
|
Sun
to
part shade
|
Well-drained,
fertile
|
Blue
to purple
|
May-June
|
Dense mats suitable as groundcover.
|
|
Veronica repens
Creeping speedwell
|
2-3
in.
|
Sun
to
part shade
|
Well-drained,
fertile
|
Blue
to purple
|
May-June
|
Mat-like groundcover; several varieties.
|
|
Viola odorata
Sweet violet
|
6-8
in.
|
Part
shade
|
Moist,
fertile
|
Violet,
white
|
May-June
|
Many varieties; potentially invasive.
|
Sempervivum
calcareum