Propagation Of Rock Plants

Pink 

Dianthus alpinus

Pinks are welcome additions to the garden and rockery chiefly for their lovely, abundant, pleasantly scented flowers, and also because they fill in the gap between the late spring and early summer flowering species. Of the approximately 270 species of annuals, biennials and perennials, the ones generally cultivated in the rock garden are D. super- bus with the scent of a linden tree, and the Common Garden Pink (D. plumarius ) with its familiar blue-green foliage, which forms large cushions and bears a profusion of flowers in May; there are a number of white, pink and red varieties. These plants will do well in any soil as long as it is not freshly fertilized, and they do not like permanent damp, as in their natural habitat they grow on rocks and sunny slopes.

One of the earliest rock garden Pinks is D. alpinus. It makes clumps of narrow, glossy green leaves and bears remarkably large, bright pink flowers. It requires a loamy-sandy, porous soil with good drainage and adequate moisture during the growing period. In winter, however, excessive damp is injuri us. It likes a slightly sheltered position in the rock garden turned away from the direct sun. D. alpinus also has creamy white variety. It should be planted in the clefts between stones, together with small species of rock plants.

Other Pink cultivated in our rock gardens include the rarer high alpine species D. glacialis with narrow, stiff, green leaves and bright pink, almost sessile flowers. It requires humus rich, lime free soil freely mixed with stones.

Shooting Star, American Cowslip

Dodecatheon meadia

The Shooting Stars, natives of North America, are striking rock garden plants with leaves forming rosettes like the Primrose and bearing a single stalk topped with a cluster of three to twelve or even more flowers. These resemble the blossoms of Cyclamen europaeum to which they are related.

A common garden species is D. meadia with broad, simple leaves and white-throated flowers. Nurserymen usually have two varieties of this species, namely the white D. meadia `Albiflorum' and D. meadia `Splendens' with somewhat larger lilac-rose flowers. D. meadia attains a height of 12 to 15 inches (30 to 40 cm.) and flowers in June.

Some of the other 30 or so species of Dodecatheon worthy of note are D. jegreyi with bright purple flowers borne on 12 inches (30 cm.) long stalks and D. pauciflorum, only 4 to 8 inches (10 to 20 cm.) high, with pink, scented flowers.

Shooting Stars do well both in semi-shade and in the sun, in loose, porous, loamy-sandy soil, rich in humus, but also in heavier soil. The position should be sheltered from the wind. The plants are most effective alongside ornamental grasses and heath plants, chiefly because they soon die back in summer which would result in empty gaps if planted elsewhere.

Propagation is generally by seed, which is sown soon after ripening, or by division of the clumps in early autumn. In winter the plants should be covered with a light layer of soil mixed with humus or peat. They do not tolerate lime.

You can visit this flower guide for more information about this article.