Home » Plants & Animals » Gardening Techniques » Impossible Gardening: Hot, Dry, Clay Soil - Part 4

Impossible Gardening: Hot, Dry, Clay Soil - Part 4

© Diana Pederson

Coreopsis

Coreopsis, sometimes called, tickseed, is a highly prized plant in the perennial border. I've grown Coreopsis grandiflora, C. lanceolata, and C. verticillata. All of these have flourished in my heavy clay soils. The daisylike flowers are typically pale yellow-gold. Some cultivars look almost like miniature, golden carnations because they are double-petaled. C. Grandiflora and C. lanceolata both have basal leaves which are different shaped from the leaves found on the upper portions of the plant. This can cause some confusion in the spring if you happen to forget that they will bush out from the clump of basal leaves that often overwinters. Both species are slightly hairy and may feel sticky to the touch.

The threadleaf form, C. Verticillata, is easily distinguished from the other varieties by its long wiry stems and threadlike leaves. I love either the pale yellow (Moonbeam) or traditional gold colored forms. Some nurseries are a pink coreopsis, C. rosea which looks like C. Verticillata. In fact, some nursery tags mistakenly identify this as a cultivar of C. verticillata. C. rosea needs more moisture than other forms of Coreopsis and did not grow well in clay soil. I'd plant this in good topsoil which tends to stay moister during the summer.

Depending on the cultivar, Coreopsis will grown from 1 to 2 feet tall. The one drawback of this plant for the enabling garden is that you must deadhead it regularly to keep it flowering all summer. If you allow it to go to seed, most of the seedlings will not look like their parents. Like other plants, cultivars do not generally reproduced true from seed although you will find some varieties as seeds--just don't expect totally consistent plants. If you want a perpetually cheerful looking plant, Coreopsis is for you. This plant has never shown pest or disease problems and is seldom fertilized.

Rudbeckias -- Black Eye Susans

These are North American native plants which provide bright, bold color from mid-summer until frost finally kills the plant for the winter. R. hirta, is the wildflower commonly called "black-eyed susan" while R. Fulgida sullivantii is the species that produces most of the named garden cultivars. All have a flower consisting of a central disc that ranges from gray to black in color with yellow or gold ray flowers (petals) which may lay flat or droop.

One of the largest flowers is on the R. Fulgida sullivantti 'Goldsturm' cultivar. This particular plant must be propagated by dividing. Seeds offered generally are not the same quality as the vegetatively produced plants.

The copyright of the article Impossible Gardening: Hot, Dry, Clay Soil - Part 4 in Gardening Techniques is owned by Diana Pederson. Permission to republish Impossible Gardening: Hot, Dry, Clay Soil - Part 4 in print or online must be granted by the author in writing.