NARGS Rock Garden Quarterly: Summer 1998

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Rock Garden Quarterly

Bulletin of the North American Rock Garden Society

Volume 56 Number 3 - Summer 1998

Features

Sedums You Should Know
by David Heller

The hot dry weather over much of the United States recently makes the latest Rock Garden Quarterly especially welcome. Those who would like to plant more heat and drought resistant plants will find lots of good suggestions here, beginning with David H. Heller's article on Sedums We Should Know. All of the plants mentioned are under one foot in height; most are readily available and most are dependably hardy.

A native of eastern North America, the white flowered Sedum ternatum is the first to flower in spring. Although it would prefer shady woodland soil, it will tolerate other conditions if not too dry. A choice, compact form S. ternatum 'Laremin Park' was discovered, propagated and introduced to horticulture by Charles Oliver of The Primrose Path nursery. Those who attended the NARGS annual meeting in Eugene, Oregon, will remember Charles as the recipient of the Marcel Le Piniec Award.

Sedum spurium 'Tricolor,' with leaves of white, red or pink and green, adds color even when not in bloom. It is described as a hardy and vigorous plant which looks good either alone or in a grouping.

Other hardy sedums with flowers of pink or yellow are mentioned and photographs show details of each.

For those who wish to try unusual sedums, two biennials and two annuals, including Sedum caeruleum, the only blue flowered sedum, are described. Its numerous blossoms are of "a heavenly color."

Latest to bloom is the much loved S. sieboldii whose lovely pink flowers last until killed by frost. This one is also a satisfactory house plant.

Sempervivums! Do We Give Them a Fair Chance?
by Rex Murfitt.

Sempervivums, the good old workhorse hen-and-chicks, are the next genus dealt with. Rex Murfitt defends these common and very tough plants by pointing out their many virtues. He also provides a short list of more desirable species in the genus and gives a few basic cultural suggestions. Photos show how attractive these Semps are.

Sempervivums: Live Long and Prosper
by Bill Adams.

In this article Bill Adams gives us a bit of background on names and history. He points out the two distinct groups: the tender from Africa and the Canary Islands; and the hardy Old World species, source of the hybrids we enjoy today. Of the five general types mentioned, Mr. Adams tells us that the tectorums are the ones most familiar to gardeners. The very popular arachnoideums (cobwebs), members of this group, tend to open wider with too much light. Try a bit of shade for a tighter plant.

Many others are mentioned by variety name, very clear photos are provided and a source is listed at the end of the article.

Jovibarbas are also discussed and photographed. With one exception they are similar in every way to Sempervivums and could be mistaken for them.

However, Jovibarba heuffelii does not produce "chicks" that can be broken off easily. It must be propagated by being cut apart. (Isn't there always one in every crowd?) Never mind, there are plenty of Jovibarbas that are more amenable.

A recent mail order catalog listed over 400 Sempervivum and Jovibarba cultivars and species. The problem here may be to limit one' s choices to a manageable number.

Sweet and Succulent: South African Mesembryanthemaceae
by Panayoti Kelaidis

In Sweet and Succulent South African Mesembryanthemaceae Panayoti Kelaidis, who has botanized in South Africa and Lethoso, writes about some of the plants he has seen and grown. In contrast to the Sedums and Sempervivums, the mesembs have been little known to gardeners until the last fifteen years.

Panayoti suggests several reasons for this, including the very large number of species and the varying demands of each, although they all want a rocky terrain.

Some members of the genus Aloinopsis have proven hardy in the Denver area. Those mentioned have attractive blossoms of yellow, pink or pink-tinged orange. All want hot, dry rocky conditions, but some have survived Denver's wet winters. Good photos show attractive yellow and deep pink blooms.

Bergeranthus jamesii, a lovely yellow daisy shown in a photo, has bloomed from April to October in Colorado.

Chasmatophyllum musculinum, another yellow flowered long bloomer, is praised for hardiness, longevity and tolerance of a wide range of soils and moisture. Panayoti says, "If you try no others, try this!"

The genus Delosperma, the Hardy Ice Plant, may be the best known and most grown of the mesembs. Descriptions of eight species and photos show flowers of deep pink, white and yellow. Some suggestions for culture are given.

The Lithops, Living Stones, have long been popular with succulent growers. Four species, L. hallii, L. hookeri, L. lesliei and L. salicola, have survived at least one Colorado winter. In the future, others may prove to be hardy also.

Stomatium, together with Delosperma and Ruschia, is the largest and most diverse genus of mesembryanthemum. Typically these plants bloom in the evening or at night, making them especially valuable to gardeners who are at work all day. S. mustellinum, said to be the hardiest in the genus, grows in a dense mound up to eight inches across.

So far, Panayoti reports, over a hundred species of mesembs have made it through at least one winter in Colorado. He expects to find that many more are also hardy.

Now that our appetites are whetted, we need to turn to the last part of the Quarterly where all the advertisements appear. One seed company in Cape Town offers seeds for over 2,000 native South African plants. I've always considered these advertisements from speciality nurseries a sort of "icing on the cake" of the Quarterly and read them as carefully as I read the body of the publication.

Dos Maihuenias
by Rod Haenni

A charming two-page mystery with a couple of good surprises, by a rock-gardener/geologist author growing these vaguely green wonders in Colorado. If they will survive in Colorado, maybe they'll survive in your garden and mine, too.

A California Rockery
by John N. Trager

A professional succulent specialist describes the development of his home garden of drought-tolerant, low-maintenance design in southern California. He begins with the thought of growing those plants he does not see at work as Curator of Desert Collections at the Huntington Botanical Gardens in San Marino, CA, but cannot resist including a number of succulents, and winds up with a garden of very interesting combinations. His description includes the complete how-it-was-built, the botanical information about the plants and how to grow them, thus giving a good roadmap to your next successful rock garden.

Florens DeBevoise
by Marnie Flook

Required reading for anyone who would like to understand what the NARGS is all about, this three-page biography of one of the three founders of the ARGS illuminates a vital gardener/writer/organizer. Here I learned that she was the one who first thought of forming a society for rock-gardeners, that she was the one who "discovered" Claude Barr, and that her nursery and writings provided much of the educational material available about Alpine Gardening until her unexpected death in 1951. A list of the ARGS recipients of the medal now given in her name is appended, the caliber of which will certainly give you a good indication of her importance to gardeners, and especially rock-gardeners everywhere. By this article, our archivist Marnie Flook has given another valuable and inspiring glimpse into the NARGS' past.

Publications Sponsored by the Society
by Marnie Flook

Here our archivist Marnie Flook describes the publications sponsored by the ARGS through the years and finishes with some future possibilities. You will want to find the ones you do not already have in your own library.

	Sedums You Should Know by David Heller The hot dry weather over much of the United States recently makes the latest Rock Garden Quarterly especially welcome. Those who would like to plant more heat and drought resistant plants will find lots of good suggestions here, beginning with David H. Heller's article on Sedums We Should Know. All of the plants mentioned are under one foot in height; most are readily available and most are dependably hardy. A native of eastern North America, the white flowered Sedum ternatum is the first to flower in spring. Although it would prefer shady woodland soil, it will tolerate other conditions if not too dry. A choice, compact form S. ternatum 'Laremin Park' was discovered, propagated and introduced to horticulture by Charles Oliver of The Primrose Path nursery. Those who attended the NARGS annual meeting in Eugene, Oregon, will remember Charles as the recipient of the Marcel Le Piniec Award. Sedum spurium 'Tricolor,' with leaves of white, red or pink and green, adds color even when not in bloom. It is described as a hardy and vigorous plant which looks good either alone or in a grouping. Other hardy sedums with flowers of pink or yellow are mentioned and photographs show details of each. For those who wish to try unusual sedums, two biennials and two annuals, including Sedum caeruleum, the only blue flowered sedum, are described. Its numerous blossoms are of "a heavenly color." Latest to bloom is the much loved S. sieboldii whose lovely pink flowers last until killed by frost. This one is also a satisfactory house plant.
	Sempervivums! Do We Give Them a Fair Chance? by Rex Murfitt. Sempervivums, the good old workhorse hen-and-chicks, are the next genus dealt with. Rex Murfitt defends these common and very tough plants by pointing out their many virtues. He also provides a short list of more desirable species in the genus and gives a few basic cultural suggestions. Photos show how attractive these Semps are.
	Sempervivums: Live Long and Prosper by Bill Adams. In this article Bill Adams gives us a bit of background on names and history. He points out the two distinct groups: the tender from Africa and the Canary Islands; and the hardy Old World species, source of the hybrids we enjoy today. Of the five general types mentioned, Mr. Adams tells us that the tectorums are the ones most familiar to gardeners. The very popular arachnoideums (cobwebs), members of this group, tend to open wider with too much light. Try a bit of shade for a tighter plant. Many others are mentioned by variety name, very clear photos are provided and a source is listed at the end of the article. Jovibarbas are also discussed and photographed. With one exception they are similar in every way to Sempervivums and could be mistaken for them. However, Jovibarba heuffelii does not produce "chicks" that can be broken off easily. It must be propagated by being cut apart. (Isn't there always one in every crowd?) Never mind, there are plenty of Jovibarbas that are more amenable. A recent mail order catalog listed over 400 Sempervivum and Jovibarba cultivars and species. The problem here may be to limit one' s choices to a manageable number.
	Sweet and Succulent: South African Mesembryanthemaceae by Panayoti Kelaidis In Sweet and Succulent South African Mesembryanthemaceae Panayoti Kelaidis, who has botanized in South Africa and Lethoso, writes about some of the plants he has seen and grown. In contrast to the Sedums and Sempervivums, the mesembs have been little known to gardeners until the last fifteen years. Panayoti suggests several reasons for this, including the very large number of species and the varying demands of each, although they all want a rocky terrain. Some members of the genus Aloinopsis have proven hardy in the Denver area. Those mentioned have attractive blossoms of yellow, pink or pink-tinged orange. All want hot, dry rocky conditions, but some have survived Denver's wet winters. Good photos show attractive yellow and deep pink blooms. Bergeranthus jamesii, a lovely yellow daisy shown in a photo, has bloomed from April to October in Colorado. Chasmatophyllum musculinum, another yellow flowered long bloomer, is praised for hardiness, longevity and tolerance of a wide range of soils and moisture. Panayoti says, "If you try no others, try this!" The genus Delosperma, the Hardy Ice Plant, may be the best known and most grown of the mesembs. Descriptions of eight species and photos show flowers of deep pink, white and yellow. Some suggestions for culture are given. The Lithops, Living Stones, have long been popular with succulent growers. Four species, L. hallii, L. hookeri, L. lesliei and L. salicola, have survived at least one Colorado winter. In the future, others may prove to be hardy also. Stomatium, together with Delosperma and Ruschia, is the largest and most diverse genus of mesembryanthemum. Typically these plants bloom in the evening or at night, making them especially valuable to gardeners who are at work all day. S. mustellinum, said to be the hardiest in the genus, grows in a dense mound up to eight inches across. So far, Panayoti reports, over a hundred species of mesembs have made it through at least one winter in Colorado. He expects to find that many more are also hardy. Now that our appetites are whetted, we need to turn to the last part of the Quarterly where all the advertisements appear. One seed company in Cape Town offers seeds for over 2,000 native South African plants. I've always considered these advertisements from speciality nurseries a sort of "icing on the cake" of the Quarterly and read them as carefully as I read the body of the publication.
	Dos Maihuenias by Rod Haenni A charming two-page mystery with a couple of good surprises, by a rock-gardener/geologist author growing these vaguely green wonders in Colorado. If they will survive in Colorado, maybe they'll survive in your garden and mine, too.
	A California Rockery by John N. Trager A professional succulent specialist describes the development of his home garden of drought-tolerant, low-maintenance design in southern California. He begins with the thought of growing those plants he does not see at work as Curator of Desert Collections at the Huntington Botanical Gardens in San Marino, CA, but cannot resist including a number of succulents, and winds up with a garden of very interesting combinations. His description includes the complete how-it-was-built, the botanical information about the plants and how to grow them, thus giving a good roadmap to your next successful rock garden.
	Florens DeBevoise by Marnie Flook Required reading for anyone who would like to understand what the NARGS is all about, this three-page biography of one of the three founders of the ARGS illuminates a vital gardener/writer/organizer. Here I learned that she was the one who first thought of forming a society for rock-gardeners, that she was the one who "discovered" Claude Barr, and that her nursery and writings provided much of the educational material available about Alpine Gardening until her unexpected death in 1951. A list of the ARGS recipients of the medal now given in her name is appended, the caliber of which will certainly give you a good indication of her importance to gardeners, and especially rock-gardeners everywhere. By this article, our archivist Marnie Flook has given another valuable and inspiring glimpse into the NARGS' past.
	Publications Sponsored by the Society by Marnie Flook Here our archivist Marnie Flook describes the publications sponsored by the ARGS through the years and finishes with some future possibilities. You will want to find the ones you do not already have in your own library.