Garden guy: Plants that thrive in clay soil

There are many different types of soil in our area, but clay seems to be more abundant than are others. On the one hand, clay soil is heavy, hard to work unless the moisture level is just right, and it can turn brick-like in heat and drought conditions.

On the other hand, it retains water and nutrients well and can be amended with compost to produce loam, which is better. But organic matter gets used up and must constantly be replaced. So, growing plants that tolerate clay soil is a smart strategy for most of us even if we continue to add organic matter regularly.

My gardening philosophy calls for maximizing the use of shrubs and perennials to try minimizing the need for new plants and the work associated with selecting and planting. Thus, I try to get shrubs and perennials that do well in our conditions. Following are a few plants that I have found do well in our alkaline, clay soil.

Shrubs include (includes perennials that are woody and shrub-like): autumn sage (Salvia greggii), barberry (Berberis spp.), blue mist spirea (Caryopteris x clandonensis), boxwood (Buxus microphylla japonica varieties), butterfly bush (Buddleia davidii and other species), Cotoneaster spp., firethorn (Pyracantha spp.), flame acanthus (Anisacanthus wrightii), heavenly bamboo (Nandina domestica), hardy Hibiscus (Hibiscus moscheutos), Lantana camara spp. and cultivars, mock orange (Philadelphus spp.), possumhaw holly (Ilex decidua), Russian sage (Perovskia atriplicifolia), snowball bush (Viburnum spp.), rose of Sharon (Hibiscus syriacus), wormwood (Artemisia spp.) and yaupon holly (Ilex vomitoria), Yew (Taxus x media varieties). Different cultivars of many of these are available giving different sizes and colors from which to choose.

Bob Hatton
Bob Hatton

Among perennials are: Aster spp., beardtongue (Penstemon spp.), bee balm (Monarda didyma), black-eyed Susan (Rudbeckia spp.), blanket flower (Gaillardia spp.), catmint (Nepeta spp.), Clematis spp., columbine (Aquilegia spp.), cranesbill (Geranium spp.), Cupid’s dart (Catananche coerulea), chocolate flower (Berlandiera lyrata), daylily (Hemerocallis spp.), false chamomile (Boltonia asteroides), Iris spp., lily turf (Lirope spicata), Mexican petunia (Ruellia spp.), Missouri evening primrose (Oenothera macrocarpa), mums (Chrysanthemum spp.), obedient plant (Physostegia virginiana), Pincushion flower (Scabiosa columbaria), plumbago (Ceratostigma plumbaginoides), purple coneflower (Echinacea purpurea), Salvia spp., Shasta daisy (Leucanthemum spp.), snow in summer (Cerastium tomentosum), soapwort (Saponaria x lempergii), spiderwort (Tradescantia virginiana), stonecrop (Sedum spp.), sundrops (Calylophus serrulatus), tickseed (Coreopsis spp.), Verbena spp., and yarrow (Achillea spp.).

These are by no means comprehensive lists, so do not be afraid to try other shrubs and perennials. However, unless you do not mind some failures, I recommend that you research those with which you are not familiar.

Most of these share the common requirement of needing good drainage. Of course, some are more tolerant than others of poorer drainage, but all will have longer lives and be healthier plants with good drainage.

Adding composted cotton burrs, coarse sand or pea gravel, expanded shale or many of the other organic and inorganic products available will help provide drainage to clay soil. If you use coarse sand, I recommend an equal amount of compost be used also.

This article originally appeared on Amarillo Globe-News: Garden guy: Plants that thrive in clay soil