PLANT FORUM: At The August 2026 Meeting
By Susi Torre-Bueno, for Let’s Talk Plants! October 2026.
For over two decades a meeting highlight was the Plant Forum, where a horticultural expert spoke about plants brought in by members. These descriptions appeared in the newsletter and are available free to the public on our website at https://sdhort.org/PlantForum. This is an alphabetical listing of the over 7500 plants which were displayed at meetings, including over 1600 detailed descriptions. Check it out when thinking about plants to add to your garden, and feel free to share this link with your friends.
After a few years on hiatus the Plant Forum is back, and we encourage all members to share some plants at the meetings. I can guarantee there will be members who will have not grown, and might not have ever seen, at least one plant from your garden.
All you have to do is:
1) Bring a cutting or potted plant to a meeting.
2) BEFORE you leave home, take a minute to fill out a slip of paper with the common and scientific name of the plant, where it is native to (if you know that), what city it is growing in, your name, and a couple of sentences about your experience with the plant.
Although I’m no expert I will do my best to talk about the plants I’m familiar with and will get help from other attendees. At the end of the meeting, we will gather up the printed information and include it in the next newsletter. If you have any questions, contact Susi Torre-Bueno at storrebueno@cox.net.
I want to thank the members who bring in plants for the Plant Forum and then donate these cuttings for other members to take home.
Bromeliad sp. Or cv. BROMELIAD
Rhet brought in a box of bromeliad pups to share. The species or cultivar is unknown, but it has red flowers in the cup area. She grows it in shade or with filtered light. Many bromeliads are described in the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum).
(Rhet Michlin, San Diego, 9/26)
Caesalpinia pulcherrima PRIDE-OF-BARBADOS, DWARF POINCIANA
(Fabaceae) Tropical America
From the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum), description by Tom Piergrossi: “This species produces red and orange flowers on a shrubby plant to about 5 feet tall. Reproduction on these is done by seed, which should be scarified (scratched) before planting. Gorgeous plantings of both this and C. gilliesii can be seen in Palm Springs. Probably as close as we’re going to get to growing Royal Poinciana (Delonix regia) from the tropics.”
(Kathryn Blankinship, San Marcos, 9/26) —T.P.
Cordia boissieri TEXAS OLIVE
(Boraginaceae) New Mexico, Texas, Mexico
From the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum), description by Steve Brigham: “This heat-loving large shrub or small tree grows slowly to 12’ tall, sometimes more with age. In summer and fall it produces showy clusters of 2- 1/2" white flowers with yellow throats. Velvety gray-green oval leaves are up to 5" long; plants are evergreen in mild climates but may be deciduous with frost. Drought tolerant, but does best with some summer water; cold-hardy to around 20°F. “
(Susi Torre-Bueno, Vista,9/26) – S.B.
Crassula falcata PROPELLER PLANT, SCARLET PAINTBRUSH
(Crassulaceae) So. Africa
From the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum), description by Cathy Tylka: “In mid-summer, showy, frothy masses of small red flowers sit on top of long stems on this sun-loving succulent species and contrast well with the sickle-shaped gray-green foliage. The mostly unbranched stems eventually form a prostrate spreading clump. New shoots then grow from the plant base and the stem tips; use these shoots as cuttings. Grows to 2-3ʹ′ tall and wide; needs good drainage and low-water in full sun to light shade. The common epithet “propeller plant” refers to the thick, tapering leaves that, “twist slightly like a propeller.” Hardy to 20°F. [Quote from Succulents for the Contemporary Garden by Yvonne Cave.]”
(Susi Torre-Bueno, Vista, 9/26) – C.T. & S.T-B.
Dais cotinifolia POMPOM TREE
(Thymelaeaceae) S. Africa
From the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum): “Pronounced with two separate syllables, Dais is a delightful small-scale tree growing 8–20 feet tall, or if well pruned is a small to medium sized shrub. It is indigenous to the eastern Cape region of S. Africa up to Natal and the northern Transvaal. Every garden in coastal Southern California should have at least one Pompom Tree as it is very attractive when covered with its loose balls or spherical pompoms of shell pink to pinkish-mauve tubular flowers that have starry-tipped slightly recurved petals. These massed flowers make an impressive show in early summer, and when in bloom will always be the focal point of the garden. If there is any drawback to Dais, it is that these floral heads persist in the manner of the pink ball tree, Dombeya wallichii—the old blossoms hang on after fading. Although it will withstand moderate frost, Dais is best grown in a frost-free sunny location. Heat resistant when given ample water (a requirement) the tree does very well planted along hot paved areas, such as parking lots. Its nonaggressiveroot system makes it ideal to plant against walls and in small spaces close to buildings and foundations. This tree does particularly well on sunny south and southwestern walls, where the heat brings out prolific flowering. Dais reacts well to heavy pruning and can be shaped into bushy shrubs or standards, and would be a good candidate for an espalier (trellis). Makes an ideal container plant for the sunny patio and as an additional quality, flower stems can be cut and last well as a vase flower indoors. What else could you ask for!”
(Susi Torre-Bueno, Vista, 9/26) —M.S.B.
Dichorisandra thyrsiflora BLUE GINGER
(Commelinaceae) Brazil
From the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum), description by Kathy Musial & Steve Brigham: “Although not a true ginger, this plant is famous for its blue flowers, and rightly so. This Brazilian native is an erect perennial typically 4-5 feet tall, occasionally taller. The deep green glossy 6–12 inch leaves are elliptic in shape, with a thick prominent midrib and purplish beneath, and spirally arranged along the stem. The flowers are produced in panicles atop each cane and are a rich royal purplish-blue. The Blue Ginger likes warm humid conditions, rich soil, part shade, regular watering and feeding, and protection from frost. Root-hardy to about 25°F. Main bloom period is for several weeks in fall after which the canes that flower should be cut to the ground. Moderate to ample water during the growing season, drier in winter (rainfall alone should be sufficient depending on the frequency). Also a good indoor plant. It is propagated by stem cuttings or division.”
(Kathryn Blankinship, San Marcos, 9/26) —K.M. & S.B.
Gymnocalycium baldianum SPIDER-CACTUS, DWARF CHIN CACTUS
(Cactaceae) Argentina
From Wikipedia: “It is a globose cactus, spherical or a little flat, with a diameter up to 8 cm, dark gray-green to blue-green in color, or sometimes brown, depressed, spherical shoots and reaches heights of 4 to 10 centimeters with diameters of 6 to 7 centimeters. It has 8 to 10 ribs with tubercle-shaped areoles, covered in groups of 6 to 8 pale grey, curved spines, giving to the species its common name of spider-cactus. Like many cacti, it does not divide but may form offsets after some years. There are no central spines. The five to seven gray or brown marginal thorns are thin, lie on the surface of the shoot and are up to 1.5 centimeters long. The funnel-shaped flowers reach a diameter of 6 cm, growing near the apex of the plant and are red, pink or orange. Flowers are 3 to 5 centimeters long and reach the same diameter. The dark gray-green fruits are spindle-shaped. Gymnocalycium baldianum is widespread in the Argentine province of Catamarca at altitudes of 1000 to 2000 meters.”
(Cathy Tylka, Escondido, 9/26)
Haworthia sp. or cv. HAWORTHIA
(Asphodelaceae)
(Rhet Michlin, San Diego, 9/26)
Leucophyllum frutescens ‘Green Cloud’ GREEN CLOUD TEXAS RANGER
(Scrophulariaceae) Horticultural Hybrid
From the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum), description by Tom Piergrossi: “Leucophyllums are underused shrubs in San Diego, doing equally as well at the coast or the inland valleys. Extremely drought tolerant, they prefer the hottest spot you’ve got. The gray foliage is a great contrast to the small-lipped purple flowers which are related to the annual snapdragon (though you wouldn’t know it by these shrubs). Not picky about soil, they need good drainage. Many cultivars exist, but are usually available only in desert regions.”
(Susi Torre-Bueno, Vista, 9/26) – T.P.
Quercus agrifolia COAST LIVE OAK
Quercus dumosa CALIFORNIA SCRUB OAK
Quercus engelmannii ENGELMANN OAK
Quercus tomentella ISLAND OAK
See descriptions of these California oaks in the article by Tony Gurnoe in the October 2026 newsletter
(Tony Gurnoe, Encinitas, 9/26) – T.G.
Ruellia brittoniana MEXICAN PETUNIA
(Acanthaceae) Mexico
From the SDHS Plant Forum Compilation (https://sdhort.org/PlantForum), description by Steve Brigham: “This is a remarkable and practically indestructible shrubby perennial that tolerates a wide range of garden conditions. It grows quickly in full sun to make a sturdy clump of around 4 by 4 feet. The upright stems are topped with dark blue trumpet-shaped flowers during warm weather. Although it is tolerant of somedrought, it prefers regular watering and is nearly ineradicable in clay soil. Evergreen in mild climates, this plant can go deciduous with heavy frost but is fully hardy to at least 10ºF or so. It is also tolerant of extreme desert heat, especially when grown in part shade. Cut back hard in late winter to keep plantings tidy and encourage new growth. White-flowered, pink-flowered, and dwarf forms of this species are also grown.”
(Kathryn Blankinship, San Marcos, 9/26) – S.B.
