A. There are many plants that are more tolerant of dry conditions than some of our beloved garden prima donnas such as bigleaf hydrangeas or hybrid tea roses. Even plants that tolerate dry conditions should be watered during dry periods for the first two or three years, until they become established. They should also be planted in areas where the soil drains well; most resent poorly drained soil.

Some of the shrubs that would work on your hillside include flowering quince, slender deutzia (Deutzia gracilis), forsythia, bayberry, mock orange, fragrant sumac, 'Snowmound' spirea, Vanhoutte spirea and chastetree. Here is a list of heat and drought-tolerant plants. To find out more about these plants, consult books in the bibliography at the end:

Trees

White fir (Abies concolor); Hedge maple (Acer campestre); Italian alder (Alnus cordata); Devil's walking stick (Aralia spinosa); Hackberry (Celtis occidentalis); Yellowwood (Cladrastis kentukea); Kentucky coffeetree (Gymnocladus dioicus); Ginkgo (Ginkgo biloba); Goldenraintree (Koelreuteria paniculata); American sweetgum (Liquidambar styraciflua); Amur corktree (Phellodendron amurense); Bristlecone pine (Pinus aristata); Lacebark pine (P. bungeana); Sassafras (Sassafras albidum); Chinese scholar-tree (Sophora japonica); Japanese tree lilac (Syringa reticulata); Japanese zelkova (Zelkova serrata)

Shrubs

Glossy abelia (Abelia x grandiflora); Five-leaf aralia (Acanthopanax sieboldianus); New Jersey tea (Ceanothus americanus); Flowering quince (Chaenomeles spp.); Gray dogwood (Cornus racemosa); Cotoneaster (Cotoneaster spp.); Smokebush (Cotinus coggygria); Deutzia (Deutzia spp.); Forsythia (Forsythia spp.); Seven-son flower (Heptacodium miconioides); St. Johnswort (Hypericum spp.); Japanese holly (Ilex crenata); Juniper (Juniperus spp.); Bayberry (Myrica pensylvanica); Mock orange (Philadelphus coronarius); Ninebark (Physocarpus opulifolius); Mugo pine (Pinus mugo); Fragrant sumac (Rhus aromatica); Saltspray rose (Rosa rugosa); Spirea (Spirea spp.); Coralberry/snowberry (Symphoricarpos spp.); Lilac (Syringa spp.); Nannyberry (Viburnum lentago); Blackhaw viburnum (Viburnum prunifolium); Chastetree (Vitex agnus-castus); Weigela (Weigela spp.); Adam's needle (Yucca filamentosa)

Annuals

Amaranthus (Amaranthus spp. & cvs.); Bidens (Bidens ferulifolia); Pot marigold (Calendula officinalis); Annual vinca (Catharanthus roseus); Cockscomb, Plumed celosia (Celosia cristata); Bachelor buttons (Centaurea cyanus); Spider flower (Cleome hasslerana); Larkspur (Consolida ambigua); Cosmos (Cosmos spp.); Strawflower (Bracteantha bracteata); Euphorbia (Euphorbia spp.); Treasure flower (Gazania rigens); Globe amaranth (Gomphrena globosa); Lantana (Lantana camara); Annual statice (Limonium sinuatum); Bush zinnia (Melampodium paludosum); Four o'clock (Mirabilis jalapa); Dwarf cupflower (Nierembergia hippomanica); Annual ornamental grasses; Moss rose (Portulaca grandiflora); Rosemary (Rosmarinus officinalis); Mealy-cup sage (Salvia farinacea); Fan flower (Scaevola aemula); Dusty miller (Senecio cineraria); Mexican sunflower (Tithonia rotundifolia); Dahlberg daisy (Thymophylla tenuiloba); Verbena (Verbena spp.); Spreading zinnia (Zinnia angustifolia); Garden zinnia (Z. elegans)

Perennials and groundcovers

Yarrow (Achillea spp.); Arkansas bluestar (Amsonia hubrichtii); Golden marguerite (Anthemis tinctoria); Sea thrift (Armeria maritima); Artemesia (Artemesia spp.); Butterfly weed (Asclepias tuberosa); Basket-of-gold (Aurinia saxatilis); False indigo (Baptisia australis); Snow-in-summer (Cerastium tomentosum); Plumbago (Ceratostigma plumbaginoides); Tickseed (Coreopsis verticillata); Cheddar pink (Dianthus gratianopolitanus); Globe thistle (Echinops ritro); Sea holly (Eryngium spp.); Spurge (Euphorbia spp.); Daylily (Hemerocallis spp.); Red-hot poker (Kniphofia uvaria); Lavender (Lavandula spp.); Gayfeather (Liatris spicata); Sea lavender (Limonium latifolium); Rose campion (Lychnis coronaria) Biennial ornamental grasses - most species; Beardtongue (Penstemon spp.); Moss phlox (Phlox subulata); Obedient plant (Physostegia virginiana); Black-eyed Susan (Rudbeckia spp.); Sage (Salvia officinalis); Perennial salvia (Salvia x superba); Lavender cotton (Santolina spp.); Sedum (Sedum spp.); Lamb's ear (Stachys byzantina); Germander (Teucrium chamaedrys); Thyme (Thymus spp.)

Bibliography

"Armitage's Manual of Annuals, Biennials, and Half-Hardy Perennials" by Allan M. Armitage (Timber Press)

"Dirr's Hardy Trees" by Michael A. Dirr (Timber Press)

"Herbaceous Perennial Plants" by Allan M. Armitage (Stipes Publishing)

"Manual of Herbaceous Ornamental Plants" by Steven M. Still (Stipes Publishing Co.)

"Manual of Woody Landscape Plants" by Michael A. Dirr (Stipes Publishing)

"Taylor's Guide to Shrubs" by Kathleen Fisher (Houghton Mifflin Co.)

"The Color Encyclopedia of Ornamental Grasses" by Rick Darke (Timber Press)