Xeriscaping: Can the Cacti

While cacti and succulents may have a place in some drought-tolerant gardens, they are not the only alternatives.

In most landscapes there are plants that survive periods of drought. Placing these plants in the garden reduces the need to supply extra water during periods of inadequate rainfall. While cacti and succulents may have a place in some drought-tolerant gardens, they are not the only alternatives. There are other choices available and appropriate for dry areas. With careful selection, planning and execution, drought-tolerant landscapes can be as pleasing as those needing heavy irrigation.

SELECT PLANTS FOR GROWING CONDITIONS. Select plants for the growing conditions in a given area when planning and designing the landscape. These growing conditions create microclimates. Define the microclimates. Create a site plan that groups plants according to similar water needs. Strive for three basic divisions: very low water zone, low water zone, and moderate water zone. Each area should be irrigated separately, according to specific water needs. Incorporate leaf size and color, bloom period, and size and shape of plant, to create visual interest.

Plants for Low and Very Low* Water Zones

    Trees and Shrubs
    Acanthopanax sieboldiana, Five-Leaved Aralia*
    Acer campestre, Hedge Maple
    A. ginnala, Amur Maple
    Amorpha canescens, Lead Plant
    Aralia elata, Japanese Angelica-Tree
    Arctostaphylos uva-ursi, Bearberry1
    Berberis thunbergii, Japanese Barberry
    Betula populifolia, Gray Birch
    Buddleia alternifolia, Butterfly Bush
    Caragana spp., Peatree
    Carya glabra, Pignut Hickory
    Celtis occidentalis, Hackberry
    Chaenomeles spp., Flowering Quince
    Cotoneaster spp., Cotoneaster
    Crategus phaenopyrum, Washington Hawthorn
    Elaeagnus angustifolia, Russian Olive*
    Genista spp., Woadwaxen
    Gleditsia tricanthos v. inermis, Honey Locust*
    Gymnocladus dioica, Kentucky Coffee Tree
    Juniperus spp., Juniper
    Ligustrum spp., Privet
    Maclura pomifera, Osage Orange*
    Myrica spp., Bayberry*
    Physocarpus spp., Nine-Bark
    Pinus banksiana, Jack Pine
    Potentilla spp., Cinquefoil
    Prunus besseyi, Plum
    Quercus macrocarpa, Burr Oak
    Q. prinus, Chestnut Oak
    Rhus spp. (esp. R. typhina), Sumac*
    Robina pseudoacacia, Locust*

    Perennials
    Rosa rugosa, Hedge Rose*
    R. virginiana, Virginia Rose
    Sophora japonica, Sophora
    Tamarix spp., Tamarix
    Vaccinum pallidum, Dry-Land Blueberry
    Viburnum lentago, Nannyberry
    Achillea spp., Yarrow*
    Aethionema spp., Stonecress1
    Alcea rugosa, Hollyhock
    Alyssum montanum, Alyssum1
    Amsonia jonesii, Amsonia
    Anacyclus depressus, Anacyclus
    Antennaria spp., Pussytoes1
    Anthemis spp., Camomile*1
    Armeria spp., Thrift1
    Artemisia spp., Wormwood, Mugwort*1
    Asclepias tuberosa, Butterfly Milkweed
    Aster divaricatus, White Wood Aster
    A. ericoides, Heath Aster*
    Baptistia australis, False Indigo
    Belamcanda chinensis, Blackberry-lily
    Callirhoe involucrata, Low Poppy Mallow1
    Campanula poscharskyana, Serbian Bellflower1
    Caryopteris x clandonensis, Hybrid Bluebeard
    Centaurea spp., Bachelor's Button
    Cerastium tomentosum, Snow-in-Summer1
    Chrysopsis villosa, Hairy Goldaster*1
    Chrysothamnus spp., Rabbitbush
    Comtonia peregrina, Sweetfern
    Coreopsis verticillata, Tickseed
    Dictamnus albus, Gasplant
    Dracocephalum spp., Dragonhead
    Echinacea purpurea, Coneflower*
    Elymus glauca, Blue Lyme Grass
    Erianthis ravenae, Plume Grass
    Eriogonum umbellatum, Sulfur Plant
    Eryngium spp., Sea-Holly1
    Eupatorium spp., Mistflower, Joe-Pye- Weed
    Euphorbia spp., Spurge1
    Festuca spp., Fescue*
    Gaillardia spp., Blanket Flower
    Guara lindheimeri, Guara1
    Goniolimon tataricum, Tatarian Statice1
    Helianthemum nummularium, Common Sunrose1
    Helictotrichon sempervirens, Blue Oat Grass1
    Hypericum cerastiodes, St.-John's-Wort*
    Hyssopus officinalis, Hyssop
    Knautia spp., Pincushion Flower
    Lavandula spp., Lavender1
    Liatris spp., Gay-Feather1
    Linaria spp., Toadflax
    Malva moschata, Musk Mallow
    Marrubium spp., Horehound
    Nepeta cataria, Catnip
    Oenothera spp., Sundrop1
    Opuntia spp., Prickly Pear*1
    Origanum spp., Oregano1
    Penstemon caeapitosus, Mat Penstemon1
    Perovskia spp., Russian Sage*1
    Potentilla spp., Cinquefoil1
    Ratibida columnifera, Prairie Coneflower*
    Rudbeckia fulgida, cultivars (i. e. Goldstrum)*
    Ruta graveolens, Rue1
    Salvia spp., Sage
    Santolina spp., Lavender-Cotton1
    Scutellaria spp., Scullcap
    Sedum spp., Stonecrop*1
    Sempervivum spp., Hens-and-Chicks*1
    Silene frivaldskyana, Campion
    Solidago spp., Goldenrod
    Stachys spp., Lamb's Ears1
    Symphytum spp., Comfrey*
    Thermopsis fabacea, Carolina Lupine1
    Thymus spp., Thyme1
    Verbascum thapsus, Mullein*1
    Verbena bipinnatifida, Dakota Verbena1
    V. canadensis, Rose Verbena1
    Waldsteinia ternata, Barren-Strawberry
    Yucca spp., Adam's Needle*
    Cosmos bipinnatus, Cosmos
    Eschscholtzia californica, California Poppy*
    Gaillardia pulchella, Blanket Flower
    Gazania rigens, Treasure Flower
    Gomphrena globosa, Globe Amaranth
    Helichrysum bracteatum, Strawflower
    Helipterum roseum, Strawflower
    Ipomoea spp., Morning-Glory
    Portulaca grandiflora, Rock-Rose*
    Sanvitalia procumbens, Creeping Zinnia
    Tagetes spp. and vars., Marigold
    Tithonia rotundifolia, Mexican Sunflower*
    Tropaeolum majus, Nasturtium
    Zinnia spp. and vars., Zinnia

Soil type, wind, and exposure to sun can create a dry microclimate in an area that receives heavy rainfall. Sandy, well-drained soil will dry out more quickly, while heavy clay soils are likely to remain moist much longer. Mixing humus into the soil will improve water-holding capacity of sandy soils and water penetration in clay soils. Sandy soils with humus will hold larger amounts of water. Clay soils amended with humus will absorb more water, reducing runoff. In locations with poor drainage and heavy soils, many drought-tolerant species may suffer during years with average or abundant rainfall. Wet winters and spring rains may also cause problems for some drought-tolerant plants growing in heavy soils.

IRRIGATION ZONES

  • Very Low Water Zone:
    This area is typically farthest from a source of water. Plants in this area must be chosen carefully, requiring little or no supplemental irrigation. Some of these plants may show problems in years of abundant rainfall.

  • Low Water Zone:
    Plants chosen for this area will require more water than that which is available naturally. During severe drought, supplementing the water supply will become necessary.

  • Moderate Water Zone:
    This zone will use the greatest ratio of water in the landscape. Keeping this area small will help limit water needs. It is possible to grow drought-intolerant plants in this area.

LIMIT TURFGRASS. Turfgrass requires more water than other plants in the landscape. By isolating turf from gardens, trees and shrubs, a lawn care operator (LCO) can separate irrigation zones and waste less water. Limit turf to areas that are regular in shape and easily irrigated. Cultivar selection should be appropriate to the climate, site, level of maintenance, intended use and reduced water consumption. Although coarse in texture and appearance, tall fescue mixes offer good heat and drought tolerance. Cut the grass at a height of 21/2 to 3 inches. Longer leaf blades help to shade and cool the ground, reducing evaporation from the soil and lessening the need to irrigate.

IRRIGATE EFFICIENTLY. Efficient irrigation may mean including an irrigation system. The least efficient system is the sprinkler. It delivers a large amount of water in a short period, but loses excessive amounts of moisture to evaporation. Sprinklers are the only choice for turf areas. Low-volume trickle or drip irrigators and soaker hoses deliver moisture over a long period, losing little water because of evaporation or runoff. Check all systems regularly. An improperly calibrated, clogged or leaking system can waste a great deal of water. Carefully probe the root zone to help determine the moisture content in the soil. With some low-volume systems, the surface of the soil will not appear to be saturated, while the root zone will receive the proper amount of moisture.

USE MULCH PROPERLY. Properly mulching an area lowers the soil temperature and decreases the loss of moisture due to evaporation. In addition to creating texture in the landscape, organic mulches decay, adding nutrients to the soil. Appropriate depth of the mulch is important: 2 to 3 inches for trees and shrubs, and 1 to 2 inches for annuals and perennials.

Carefully planned landscapes and sound cultural practices reduce water needs. Controlling weeds will lower moisture competition with other plants. Lessening competition will strengthen existing plants and make them less susceptible to disease, insects and drought. By carefully preparing and meeting plant requirements, an LCO can develop a landscape full of color and texture, while reducing water requirements.

This fact sheet provided by The Ohio State University Horticulture and Crop Science Extension office.

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