Tulips by Quite Another Name

The Culture of Anguloas by Linda Kraus

Anguloa × ruckeri Lindl. photographed at the Fuqua Conservatory, Atlanta Botanical Garden. Photo © 2006 Greg Allikas

The orchidist attracted to that which is exotic, otherworldly, and fantastic in the Orchidaceae eventually is seduced by anguloas. My initial interest was directed to pollination mechanisms of the genus (probably involving male euglossine bees: Eulaema boliviensisEulaema cingulata), a natural progression from similar interests in the pollination of coryanthes and stanhopeas. For those orchidists not interested in the mysteries of pollination, surely the stunning, long-lasting flowers are an inducement. They often are the awesome centerpiece of a modestly floriferous summer greenhouse.

A neophyte who wants to grow anguloas with profuse blooms often is told that the culture is exactly the same as that for lycastes. This thesis is supported by the relative cultural ease in blooming angulocastes. The other pat response is for the grower simply to simulate the cultural conditions of the anguloas' native Andean habitats. Perhaps both assertions are simplifications and are less important than the assurances that anguloas are difficult to kill (unless you repeatedly mist their young, plicate leaves and dare the plants to rot) and that the plants are naturally floriferous.

Anguloa uniflora Ruiz & Pav. photographed at the Fuqua Conservatory, Atlanta Botanical Garden. Photo © 2006 Greg Allikas

Through researching other growers' cultural secrets, I have learned that regional practices differ. There appears to be no definitive body of cultural advice, surely odd for a genus of 10 species that have been written about in horticultural manuals since the 1700s. Although it is possible to bloom anguloas under lights, the relatively large plant size and the grower's attempts to produce those simulated Andean cool air currents make them poor choices for limited light garden space.

Jerry Fischer of Orchids Limited in Minnesota grows several of the common Anguloa species (clowesiicliftoniiruckeristrobelii) and the rarer Anguloa hoenlohii with considerable success. He uses both clay and plastic pots containing a special mix of medium fir bark, medium charcoal, perlite, redwood wool, and coarse peat in the following proportions: 3 cubic feet of bark to a 10" pot of perlite, a 10" pot of peat, 1-1/2 10" pots of charcoal, and 1-1/2 10" pots of redwood wool.

He waters his anguloas every four to five days in winter (contingent on weather conditions) and every three days in summer. Most importantly, he uses only rainwater. He fertilizes regularly with a 30-10-10 analysis fertilizer and is careful to provide 58-60ºF night temperatures and 65ºF day temperatures in winter and 60ºF night temperatures and controlled 80ºF day temperatures in summer. He relies on an evaporative cooler to maintain these crucial levels. Growing his anguloas along with lycastes, he has no problems getting his plants to bloom profusely.

Hermann Pigors of Oak Hill Gardens in Illinois grows his anguloas with some cultural variance. He is insistent upon greenhouses that are tightly insulated, thereby creating a desirable humid atmosphere for the anguloas. He mists his anguloas as often as five times a day in the summer and is careful to bring his summer temperatures down to 55ºF at night.

Pigors' preference is for clay pots and a fairly coarse mix: 30 bags (3 cubic feet) of medium-grade fir bark to 4 bags (3 cubic feet) of redwood chips and fiber to 1 bag (4 cubic feet) of perlite to 1 bag (4 cubic feet) of vermiculite to 1 bale (5 cubic feet) of selected Manitoba coarse peat moss. This mix has been very successful and has been tested over a 13-year period of growing mixed genera. Obviously, it would work well for lycastes and intergenerics in this group. He feeds his plants on a regular two-week schedule, using a 30-10-10 analysis fertilizer, but occasionally he will use a 20-20-20 analysis and highly recommends the addition of Follett's 8-8-8. The plants grow very easily and bloom predictably.

Anguloa virginalis Linden ex B.S.Williams photographed at Golden Gate Orchids, San Francisco. Photo © 2007 Greg Allikas

Marie Riopelle from the Pacific Northwest is a magical grower of cool species and hybrids. Her plants are dazzling cultural achievements despite the difficulties peculiar to the climate of Portland, Oregon. She and her husband, Jim, grow their anguloas in the same manner as their angulocastes. She stresses good drainage and prefers plastic pots with the same mix that she uses for miltonias and paphs. It is composed of bark, charcoal, perlite, and lava rock. She argues against the use of pumice rock, which becomes clay-like in the Portland climate. Mrs. Riopelle fertilizes every time that she waters, and her watering is determined by the amount of available sunlight. In summer, watering sometimes is done as often as every five days. The summer fertilizer is Peters 30-10-10. A 10-30-20 analysis fertilizer is used in winter. As do other meticulous growers, she is very consistent about temperature levels, keeping the winter day temperature at 68ºF and the night between 56-60ºF, and the summer night temperature between 60-68ºF with an evaporative cooler. Her plants pose no special problems and bloom generously.

California growers differ widely in their cultural practices for anguloas. Robert Levi, whose exquisite plant of Anguloa cliftonii 'Cancer' received a Certificate of Cultural Merit from the American Orchid Society (with Ron Hawley of Hawley-Levi Orchids), uses a standard mix of tree fern and bark in plastic pots. He advises growers to use Styrofoam "peanuts" for drainage. He stresses that what might work well for him in one part of the state would not necessarily be recommended for a grower a valley away.

Another California grower, Bruce Cobbledick of Unicorn Orchids, who grows the common Anguloa species, uses plastic pots with a mixture of bark and perlite and also recommends plastic peanuts for drainage. He fertilizes every two weeks with a 30-10-10 or a balanced analysis fertilizer, but he does grow his anguloas drier during the winter months. He repots every spring and can count on his plants flowering faithfully each year. Cobbledick is careful to maintain 55ºF night temperatures and to keep his greenhouses under 80ºF during the day, so that the anguloas and lycastes can be grown with odontoglossums and other cool genera.

Anguloa clowesii Lindl. Photo © 2006 Greg Allikas

I grow all the orphaned and identified Anguloa species for which I can commit space in a large greenhouse surrounded by pine trees. Despite the filtered sun, which is less intense than I would wish, the plants all thrive and bloom predictably, if not lavishly. I use plastic pots with a simple mix of medium fir bark and medium tree fern in equal proportions. The plants are watered approximately every seven days in winter and substantially more often in summer. I do not "rest" the plants after flowering, but I give them less water.

I am assiduous in keeping the winter night temperature of my plants at 50ºF, with the summer night temperature at 65ºF or lower. I use an evaporative cooler to maintain these levels. I fertilize at each watering with a 10-30-20 analysis fertilizer, alternating with 18-18-18. Occasionally, my anguloas will exhibit hard scale - the only genus in the greenhouse so afflicted. The scale is controlled easily with malathion or Orthene. I find anguloas resistant to other common greenhouse pests and problems.

The long-lasting, colorful flowers of anguloas should tempt every orchidist. Some members of the genus, Anguloa uniflora in particular, are overwhelmingly fragrant. All species within this group are striking with their long, erect inflorescences holding showy, magnificent flowers that are ample reward for a species fancier's efforts. They are the stuff of dreams.

republished from the AOS Bulletin, vol. 56, Number 1, January 1987 with updated photos