Candlestick bush or Senna alata, grows as a small perennial tree or shrub with flowers that are bright yellow, upright racemes, that look like a candlestick.
Native to parts of the tropics, this plant commonly grows in diverse habitats. It will thrive at elevations of around 1200 m in its native tropics (e.g. South America, West Indies).
This perennial, also known as Emperor’s candlestick, is grown both as an ornamental plant and for its important medicinal value, particularly in parts of Southeast Asia, North America, and Africa.
History
This plant originates from South America and was first introduced to Hawaii in the mid-1800s. It was named by William Roxburgh, a Scottish botanist, and surgeon, in 1832.
The common name of Candlestick bush has many synonyms. Even the botanical name has several alternatives, such as Cassia alata and Cassia herpetica.
Senna alata is now classified as a high-risk, invasive species of plant in the Pacific Islands because it shades out native flora with its thick, dense foliage.
Plant Facts
| Scientific name | Senna alataCassia alata Cassia herpetica, Herpetica alata |
| Common names | Candlestick bush, |
| Genus | Senna |
| Family | Fabaceae |
| Height | 9 to 13 feet (3.96 m) |
| Width | 6 to 15 feet (4.57 m) |
| USDA Plant Hardiness Zone | Zones 10 to 11 (grows as an annual in zones 7 to 9) |
| Native to | Tropical America |
| Blooming season | Late Summer to Autumn |
| Flower colors | Yellow |
| Plant specific features | Considered to be an environmental weed outside its native range, and quick to take over from natural species. |
How to Plant and Grow a Candlestick Bush
Where to Plant
It is important to remember this plant’s status. In certain places, candlestick bush is classified as an invasive species. This means that, outside its natural area, it poses a threat to the natural flora making up the landscape.
Fire ants are attracted to the candlestick bush, so you may wish to plant it away from the house.
Senna alata is sometimes planted in front of a house or property, to act as a windbreak in the hurricane season. During the tempest, the candlestick bush can take the brunt of the hurricane-force winds, saving a house from damage or destruction.
Once the storm has passed, the candlestick bush will be completely ragged and the leaves will be all shredded. However, they will quickly grow back, and the plant will flower again soon afterward.
Due to its potential large size, and quick growing habit, you need to make sure you plant Senna alata somewhere that the shrub will have space to grow.
When to Plant
It’s very easy to grow the candlestick bush from seed. Sow seeds in the spring after all danger of frost has passed.
Candlestick Bush Care and Maintenance
Soil
Senna alata will grow in a variety of soil, from acidic to slightly alkaline, to clay and sand. It is necessary to ensure that the soil is free-draining. This will prevent the plants from rotting, especially in cooler weather.
Water
Candlestick bush plants will need some regular watering whilst they are young seedlings. At this stage of their development, it is important they do not dry out. Once established, however, they can tolerate drought conditions.
Fertilizer
This is a shrub that grows wild, flowers and self-seeds to the point that it has become a species on the invasive plant list of many regions. But, if you are growing this plant either as an ornamental shrub or for its alleged, medicinal uses, then it is recommended to apply fertilizer.
During the growing season, you can apply a general purpose fertilizer once a month, or a slow-release, multipurpose product annually. Applying fertilizer, and additionally, a mulch, will give you the best results in terms of plant health and flower production.
Sunlight
Candlestick bush needs full sun to perform best, so choose a spot that receives a minimum of six hours of sunlight each day.
Pruning and Repotting
Pinching out the tips of new growth in the Spring will encourage branching. This will give you more flowers and a much denser shrub. In the spring, you should also prune the Senna alata. Cut it back hard to increase flower production the following year.
If you are looking to repot or replace your candlestick bush plants, then gather the seeds in the fall and overwinter them in a cool, dry place ready for potting up to germinate the following spring.
You may be growing your Senna alata in a cooler region, where it will not be winter hardy. You can try to plant it in a container and overwinter it indoors. However, unless you have a very sunny room or a greenhouse, this is unlikely to be successful.
Even with a greenhouse, it is quite tricky to keep a candlestick bush indoors over the winter. The shrubs will be much more vulnerable to attack by aphids and other pests. For the best chance of success, plant in as sunny a position as possible and reduce watering.
Propagating
Propagation by seeds is very easy. The seeds form inside hard seedpods. Leave them on the plant to completely dry. Once dried, you can harvest the seeds by breaking open the hard, outer case.
The candlestick bush plants produce lots of seeds that can be overwintered until the spring and then potted up to germinate.
If you are concerned about not spreading this plant, simply cut off the seedpods or, better still, deadhead the flowers before they go to seed.
You can also divide the roots into clumps, and multiply your candlestick bushes easily like this. Simply dig up a root ball, divide it, and replant the shrubs, allowing sufficient space for them to grow.
Propagation of senna alata by cuttings is also possible. Take cuttings in the summer, from the current season’s growth, once it has started to go “woody”. These are known as semi-ripe cuttings, and you will find the plants sprout roots easily.
Pests and diseases
This plant is itself declared a pest in many regions, so check your region before growing candlestick bush.
If you have decided to overwinter your candlestick bush indoors and planted it in a container, then there is a real risk that aphids and other pests will infest your plant.
The best way to combat insect problems with your senna alata is to spray the leaves with water and check the undersides of the leaves regularly for insects and/or their eggs. Caterpillars sometimes eat both foliage and flower buds.
If plain water is not sufficient to rid your plants of this problem, try using an organic solution, such as a spray made with horticultural oil or insecticidal soap made from neem.
Temperature and Humidity
This is a tropical and subtropical plant, that will not survive where temperatures fall much below freezing for any length of time. If temperatures plummet to around 0° for a short spell, then the above-ground parts of the plant will die back to the ground.
However, the roots will survive and send up new stems from the base of the plant.
If your climate is such that it is not warm enough to grow candlestick bush, you can grow it as an annual. Because Senna alata self-seeds, or if you collect the seeds from the seed pods, you can re-sow the following spring in a protected location.
Because the plant doesn’t flower until well into the summer, it will flower in its first year and continue to flower until the temperatures fall again.
Candlestick bush likes humidity, so keep it moist, especially during prolonged dry spells. In nature, this plant is often found in wet soil and on flood plains.
One of the main reasons for this plant to have become invasive is its ability to adapt. It can tolerate drought and waterlogged ground.
Other Uses for Senna alata
This shrub is grown as a medicinal plant, as well as for its ornamental flowers. It’s known colloquially as the ringworm bush because of its effective antifungal properties. It is used to treat ringworm and other fungal infections.
Candlestick bush leaves, sometimes crushed and mixed with oil are sometimes added to shampoos and soap to treat fungal conditions. There are other medicinal uses for Senna alata, such as a laxative and purgative.
This medicinal herb is used in the tropics to treat many diseases including typhoid, diabetes, malaria, asthma, as well as several skin conditions. All parts of the plant are used, including seeds, leaves, and flowers.
Types of Senna alata You Can Grow
Although most usually, S. alata syn. Cassia alata is grown as a low-growing, multi-stemmed shrub, it is possible to train it to become a tree. If properly done, a well-trained candlebush makes an attractive specimen tree.
Conclusion
This evergreen shrub has masses of flower spikes in bright golden yellow that last from mid-summer to late fall. Being low maintenance, and fast-growing, this shrub provides color at the end of the season which is useful.
If you have the climate, and a planting spot in full sun, then it is worth growing candlestick bush.
*image by SuradechK/depositphotos
