Cassias add yellow blooms to coastal, fall landscapes
We’re in the season when social media is lit up with gorgeous images of flowering shrubs. The sasanqua camellias are particularly beautiful this fall, and how about the reblooming azaleas like Encore and newer Perfecto Mundo from Proven Winners?
I tend to blame the weather for a lot of garden happenings, and I believe the brutal cold we had late last winter is responsible for the flowering display we’re enjoying now.
But there are other fall/winter blooming shrubs that can be overlooked when the focus is on camellias and azaleas. Among them is the group of cassias that bring a yellow flower display to landscapes.
Cassias are found primarily in the coastal counties, as they are a more tropical-like landscape shrub. Every year about this time, I expect to receive more than a few questions about this plant, as the bright-yellow flowers seem to burst forth out of nowhere.
The most common cassia found in the landscape is winter cassia, known botanically as Senna bicapsularis. Since this shrub is usually at its peak flowering most years in December, another common name is Christmas Senna.
Flowering generally starts in mid-November with loose, golden-yellow clusters that have up to 12 blooms. The individual flowers each have five petals with curving stamens and pistils that protrude from the center.
I remember being in Charleston, South Carolina, a couple of years ago in November and seeing the winter cassia in bloom everywhere. I really liked one yard where the yellow flower clusters cascaded over and through the wrought iron on a bright-white, brick fence. The contrast was beautiful.
The large flower clusters form towards the ends of the slender branches and can be so heavy that the branches are pulled down, giving many plants a distinctive vase-shaped form. Winter cassias can reach about 6 feet tall and can be pruned to keep the arching branches tidy.
Another cassia I like that is rather uncommon in the landscape is the candlestick cassia. It is known botanically as Cassia alata, although there may be some confusion about the exact botanical name.
The flowers of candlestick cassias are more formal than those of winter cassia. The bright-yellow blooms are cup-shaped and arranged in tight, upright clusters reminiscent of a candlestick, hence the accurate common name.
This plant has large, tropical-looking foliage. Each compound leaf is up to 30 inches long, with the individual leaflets being 5 inches long.
Cassias are generally forgiving in the landscape, as long as they’re grown in the full sun, They require very little annual maintenance other than some occasional pruning.
Good drainage is required, as cassia don’t like to have soggy bottoms in landscape beds. On the other hand, these shrubs don’t survive well in the dry conditions that can occur in our Mississippi landscape. So be sure to maintain consistent soil moisture.
Since both of these cassia selections are considered tropical, meaning they thrive in U.S. Department of Agriculture zones 9-11, they will routinely die back to ground in the coastal counties. I believe the plants would make great container plants for northern Mississippi.
You can bring cassias indoors during the winter months or simply grow and enjoy them as gorgeous fall to early winter annuals.