If you are looking for a low-maintenance annual flower in a shady location, one that blooms prolifically, and for an extended period of time, consider browallia.
Botanically, browallia (Browallia speciosa) is a tropical perennial but it’s mostly grown as a warm-weather annual. It is a moderately fast grower with a cushion-like growth habit. Planted in groups in a flower bed or a rock garden, the deep green foliage will nicely fill the space over the summer.
Browallia is especially pretty when cascading down a wall. Its flowers attract hummingbirds.
It is also a popular plant for containers and hanging baskets. Potted plants can be brought indoors for overwintering before the first fall frost.
|Botanical Name||Browallia speciosa|
|Common Name||Browallia, Amethyst flower, Bush violet, Sapphire flower|
|Plant Type||Perennial grown as annual|
|Mature Size||One to two feet height, one to two feet spread|
|Sun Exposure||Full sun to part shade|
|Soil Type||Sandy, clay, loamy|
|Soil pH||6.1 to 7.5|
|Bloom Time||Summer to fall|
|Flower Color||Blue, purple, white|
|Hardiness Zones||10 and 11|
|Native Area||South America|
How to Grow Browallia
Except for pinching back the plants to encourage bushiness, browallia requires little maintenance.
Whether you buy browallia seedlings from a nursery, or start your own from seeds, make sure that when planting browallia in flower beds or borders, to space them at least nine inches apart.
Browallia can reseed itself but will only reach the flowering stage in zone 10 or 11; in all other zones, the growing season is too short.
In hot climates, browallia should be grown in partial or dappled shade. It prefers afternoon shade. In cooler locations, it can also tolerate full sun.
Make sure the soil does not dry out and keep it evenly moist but not soggy. Too much water on the other hand will result in mainly foliage and few flowers.
Temperature and Humidity
Browallia is a tropical heat-loving plant. Only plant it outdoors after all danger of frost has passed and temperatures have warmed. Even a very light frost can damage the foliage.
If you start out with good, rich soil, browallia will only need moderate fertilization. Apply a low-nitrogen fertilizer a couple of times during the growing season. Too much fertilizer will result in mostly foliage instead of flowers.
Grown in containers however, browallia needs more frequent fertilization, about once a month depending on frequency of watering.
Other Browallia Species
Another browallia species offered by seed companies is Jamaican forget-me-not (Browallia americana). It is often referred to as Amethyst flower or Bush violet—the same common names as Browallia speciosa.
It is also grown as an annual that blooms prolifically until the first frost. For the Browallia americana follow the guidelines for Browallia speciosa except that the plants have a more shrubby growth habit and might require staking.
Browallia americana attracts butterflies and bees.
Growing in Containers
Browallia is a popular plant for containers and hanging baskets. Keeping in mind that it’s a shade plant, choose a location where the plant is not exposed to direct hot afternoon sun.
Growing from Seeds
Start seeds indoors eight to ten weeks before last frost in your area. Because the seeds require light to germinate, just press them lightly into the soil and keep the soil evenly moist and the temperature around 75 degrees F. The seedlings emerge in seven to 21 days.
Before planting them outdoors, the young plants must be hardened off.
It is possible to overwinter your container plants if you have a large, south-facing window. Bring them indoors before nighttime temperatures fall below 40 degrees F, and cut the plants back to a manageable size. Keep the soil consistently moist but not wet.
In hardiness zones 10 and 11, you can also sow browallia in pots in the fall for winter blooming. Start the seeds in small pots and move them to a larger containers as they grow.
Browallia does not have serious disease issues. They might be visited by soft-bodied insects such as aphids, thrips, spider mites, leafhoppers, and whiteflies. These can be controlled with insecticidal soap but browallia is especially sensitive to chemicals in warm weather, which can lead to leaf damage. Weigh whether it’s a real infestation that needs to be treated, or whether the insects can be removed simply with water from the hose.