Growing a thriving community of African violets in a single pot

African violets (Saintpaulia ionantha) are known as the world’s most popular houseplant. But the communal grouping sitting on my kitchen counter is not your grandmother’s collection of individually potted plants.

Instead, they are planted together in one large glazed bowl 8-inch deep and 19- inches in diameter. Their thick lush green leaves measuring 4- inches long and 3- inches wide and the well-formed 2-inch wide blossoms indicate the violets are happy and healthy. (Note a 6-inch long teaspoon in above photo for perspective)

For more than 20 years, I have successfully grown African violets grouped together in this exact bowl despite planting advice to the contrary. Although horticulturists advocate the use of a separate pot for each violet (approximately one-third the plant’s diameter), this community of African violets are thriving. The habitat and history of these violets provide a clue as to why.

Habitat and history

Growing multiple African violets in a large container mimics their native habitat – a rainforest floor of porous, loose, fertile soil. Such violets are endemic to the Usambara Mountains, which are part of the Eastern Arc Mountain Range, a nonglaciated area with consistent climate. The Usambaras are located in the northeastern part of Tanzania, between Mount Kilimanjaro and the Indian Ocean region of Tanga.

In 1498, Portuguese explorer Vasco da Gama was the first European to view the Usambaras. In 1848, German adventurers and Protestant missionaries Johannes Rebmann and Johann Ludwig Krapf were the first to cross the range and view the enormity of these virgin forests, many of which were eventually cleared for agricultural use not only by European settlers but the Bantu, Sambaa and Massai people.

Today, scientists often call this area “African Galapagos in the clouds” because it is home to species unique only to these mountains. For example, the Eastern Arc Mountain Range houses more than 2,800 plant species, 30 species of amphibians and reptiles (15 of which are endemic) and 684 tree species. Receiving most of the rain that falls from March through May, the eastern Usambaras attracted German settlers from 1885 to 1919 with its pleasant climate and lush flora – a welcomed relief from the heat of the arid African savannah.

In 1892, after the governor of German East Africa, Baron Walter von Saint Paul, sent to his father in Germany the seeds from a hairy leafed purple flowering plant he discovered on the forest floor, the violet was on its way to becoming a popular houseplant worldwide. By 1893, the first African violets were commercially reproduced and given the generic name of saintpaulia in honor of the family. By 1926, seeds were imported to Los Angeles and 10 hybrids were developed, the most famous being “Blue Boy.” Since then hundreds of cultivars of varying flower and leaf colors, shapes and sizes have been developed.

Horticultural needs

African violets are considered “shade-adapted” plants that do not need direct sunlight but can adjust to and grow in most inside environments with the proper lighting. They also adapt to the warm temperatures and dry air of most homes. Since African violets are prone to rot in hot weather and their growth tends to slow with cool temperatures, they prefer temperatures above 60 degrees at night and between 80 to 85 degrees during the day.

Exposure to a north- or east-facing window is recommended. On the other hand, my African violets grow fine with exposure to a southwest-facing kitchen window that is shaded in the winter by horizontal blinds and protected in the summer by an outside black window screen and a retractable awning.

Correct watering is essential. African violets prefer moist well- drained soil and dry foliage. Ring spots or chlorosis can develop when sunlight shines on wet leaves or if chilled by cold water. Experts recommend that leaves do not touch adjacent plants to reduce Botrytis cinerea, a fungus that causes lesions on the underside of a leaf eventually turning it brown to black. To avoid such, I regularly monitor the overlapping leaves of my closely grouped violets. I would rather pinch off several infected leaves in  than lose several plants.

Excessive moisture can also lead to root or crown rot from the fungus Pythium ultimum. That’s why I carefully water using a small plastic watering can with a long spout. To avoid chilling the plants, I use room temperature water and slowly inch my way around the pot’s edges to ensure the leaves remain dry. Whatever size pot you choose for your African violets, growing them as a community is certainly worth a try.

 Launa Herrmann is a Master Gardener with the University of California Cooperative Extension office in Fairfield. If you have gardening questions, call the Master Gardeners office at 784-1322.