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no. 7.231

Xeriscaping: Garden Flowers

by J.R. Feucht and J.E. Klett 1


Quick Facts...

  • A xeriscape is a water-conserving landscape design.
  • Flowers add color to xeriscape yards and Gardens.
  • Improve soils before planting most flowers.
  • Soil improvement is easier if only annual flowers are used for the first year or two.
  • Plant flowers according to site exposure.
  • Spring-flowering bulbs are drought-evaders and make good flowers for a xeriscape.

Garden flowers provide showy, colorful displays in a xeriscape Garden. Xeriscape (zer-i-skap) is a water-conserving landscape. Annuals and perennials can be integrated with shrub borders and groups of trees, or they may be planted in their own beds along fences, walls, walks and patios.

Soil Conditions and Exposure

Before selecting Garden flowers, check your soil. Most flowers do poorly in heavy clay, due to lack of oxygen to their roots. Sandy soils may have poor water-holding capacity and be low in available minerals. If either extreme is true in your yard, do not plant perennial flowers the first year or two.

Improve the soil with sphagnum peat or compost, available in bales or bags at Garden centers. Incorporate 1 cubic foot of sphagnum or compost per 8- by 10-foot area to a depth of 9 inches. Plant only annuals so it will be easier to cultivate and incorporate additional organic matter in the fall, after the plants are killed by frost. Add more sphagnum or compost each year until the soil is easily worked and does not compact. Perennial flowers may then be planted.

Select plants that are compatible with the exposure. For north sides of structures or among shrubs, choose plants that tolerate less sun. For example, perennials for a shaded spot might include canterbury bells, primrose and violets. Such plants usually need cool, more consistently moist soils than most Garden flowers. They can, nevertheless, be useful in the shaded parts of a xeriscape. Add organic mulches such as wood chips to reduce watering frequency.

Bulbs

Most bulbs do best in full sun, but they must have well-drained soils. Spring-flowering bulbs are well-suited for xeriscape plantings because they are drought-evaders. That is, they grow in the cooler, more moist spring and fall seasons and lie dormant underground during the hot summer months.

Use tulips, grape hyacinths, hyacinths, daffodils and crocus for naturalizing a xeriscape. In fall, plant spring-blooming bulbs in the areas you want them. For more information on bulbs, refer to fact sheets 7.410, Fall-Planted Bulbs and Corms, and 7.411, Spring-Planted Bulbs, Corms and Roots.

Annuals

Almost all annuals commonly sold do well in xeriscape Gardens with some soil preparation and no more than one good watering a week (1 to 2 inches). For hot, dry exposures, the most reliable include marigolds, zinnias, cockscomb, sweet alyssum and bachelor's button. Where soils are shaded and cooler, use annuals such as lobelia, pansy and forget-me-not.

Rock Gardens

Rock Gardens can be an attractive addition to a xeriscape Garden. Put them in logical areas such as steep sunny slopes, rather than as mounds in the middle of a yard. Strive for a natural look and avoid a "rock pile" look or "Garden of rock" look. For more information on rock Gardens and the plants to use, refer to 7.401, Rock Garden Plants.

Table 1: Perennial plants for shady spots.
Plant NameFlower Color Flowering Time Height (ft)Remarks
Aconitum napellus
Monkshood
Purple June-
Sept.
3 to 4 Use in dense shade.
Anchusa azurea
Anchusa (Italian bugloss)
Deep blue June-July 3 to 5 Tall accent.
Aquilegia spp.
Columbine
White, blue, pink, yellow May-June 1 to 2 Use with shrubs.
Campanula medium
Canterbury bells
Pink, purple, whiteJune-July 3Tall accent.
Campanula spp.
Harebell
Blue, white June-
Oct.
1 Useful edging.
Dicentra spectabilis
Bleeding heart
Deep pink April-June 1 1/2 Use with shrubs, north sides.
Dictamnus albus
Gas plant
White, pink June-July 2 to 3 Use with shrubs.
Iberis sempervirens
Candytuft
White April-June 1 Foliage evergreen.
Lobelia cardinalis
Cardinal flower
Bright red July-
Sept.
2 Use in dense shade.
Physostegia virginiana
Dragonhead (false)
Lavender, white Aug.-
Sept.
3 to 3 1/2 Aggressive creeper.
Primula spp.
Primrose
Yellow, red, blue April-May 1/2 Showy spring flowers.
Thermopsis rhombifolia
Golden banner,
false lupine
Yellow May 1 to 2 Aggressive creeper.
Viola cornuta
Horned violet, viola
Various May-
Sept.
1/2 Shade or sun.
Viola odorata
Sweet violet
White, purple April-May 1/2 Aggressive creeper.

 
Table 2: Perennials for sunny spots.
Plant Name Flower ColorFlowering TimeHeight (ft)Remarks
*Achillea spp.
Yarrow
Yellow, white, pink July-
Sept.
1 to 3 Adapts to very poor soils; fern-like, aromatic foliage.
*Armeria maritima
Thrift
Pink May-Aug.1Grass-like foliage.
*Asclepias tuberosa
Butterfly weed
Orange July-Aug. 1 to 1 1/2 Grows in poor soils; very deep-rooted.
Aster novae-angliae
Aster (New England)
Purple, white Sept. 3 to 5 Showy for fall.
Aurinia saxatilis
Basket-of-gold
Yellow April 1 Reseeds readily.
*Cactus
(various plant groups)
Cactus
Various May-Aug. Various Use in sandy soils.
*Centaurea cyanus
Cornflower
Blue, white May-
Sept.
2 Border plant, cut flower.
*Coreopsis lanceolata
Coreopsis
Yellow June-Aug. 3Easy to grow in most soils.
Delphinium hybrids
Delphinium
White, purple, blue June-July 4 to 6 Tall accent; may need staking.
Dendranthema coccineum
Painted daisy
White, pink May-July 2 to 3 Showy, cut flower.
Dianthus barbatus
Sweet William
White, pink, red May 2 Aggressive biennial.
*Echinacea purpurea
Purple coneflower
Yellow, purple Aug.-
Sept.
4 to 6 For tall background.
*Eriogonum umbellatum
Sulphur flower
Yellow May-June 1/2 Grows in poor soils.
*Gaillardia aristata
Gaillardia, blanket flower
Red-orange June-
Sept.
2 One of the best for xeriscapes.
Gypsophila paniculata
Baby's breath
White July-
Sept.
2 1/2 Lacy, bush-like.
Hemerocallis spp.
Daylily
Yellow, red, orange June-July 2 to 2 1/2 Spreads to large clumps.
*Iris hybrids
Bearded iris
Various May-June 1/2 to 3 Easy to grow.
*Lavandula angustifolia
Lavender
Lavender July-Aug. 1 Fragrant; shrub-like.
Leucanthemum x superbum
Shasta daisy
White July-Aug. 2 to 2 1/2 Useful with shrubs.
*Liatris scariosa
Gayfeather
Lavender July-
Sept.
1 to 2 Showy in late summer.
*Linum perenne
Blue flax
Blue May-
Sept.
1 1/2 Almost shrub-like.
Lupinus polyphyllus
Lupine
Various June-Aug. 2 1/2 to 3 Good accent with shrubs.
Monarda didyma
Beebalm
Red, pink, violet, white June-July 2 to 3 Best in mass plantings.
Paeonia hybrids
Peony
White, pink, red May-June 2 to 2 1/2 Tolerates some shade.
*Papaver nudicaule
Iceland poppy
Orange, reds, white, pinks April-June 1 Good edging plant.
*P. orientale
Oriental poppy
Orange, salmon, red May-June 1 1/2 to 2 Aggressive creeper.
*Penstemon spp.
Penstemon
Red, white, blue June-July 2 to 3 Many varieties.
Phlox paniculata
Garden phlox
White, lavender, pink May-July 1 to 1 1/2 Easy to grow.
*Rudbeckia hirta
Black-eyed Susan
Yellow July2 to 3 Needs space.
*Rudbeckia laciniata 'Hortensiana'
Golden glow
Yellow July-
Sept.
5 to 6 Tall, late summer flower.
*Scabiosa caucasia
Pincushion flower
Lavender May-Aug. 1 to 1 1/2 Fern-like foliage.
*Sedum spp.
Sedum, stonecrop
Various May-
Sept.
1/2 to 1 Many varieties; succulent foliage.
Veronica spicata
Veronica
Purple May-June 2 to 4 Aggressive creeper.
Viola cornuta
Horned violet, viola
Various May-
Sept.
1/2 Shade or sun.
*Zinnia grandiflora
Paperflower
Yellow June-
Sept.
1/2 Long-lasting bloom.
*Most drought-enduring.

1J.R. Feucht, Colorado State University Extension landscape plants specialist and professor (retired); and J.E. Klett, Extension horticulture specialist and professor; horticulture and landscape architecture. Prepared in cooperation with the Technical Advisory Committee for Xeriscape Front Range, an affiliate of the National Xeriscape Council, Inc. 6/00.

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