Alternanthera [Al-ter-NANTH-ur-uh] aka (Joseph’s Coat plant) is a genus of more than 200 species of tender perennial and bushy annuals grown for their colorful foliage as garden plants and indoor plants.
This plant belongs to the Amaranthaceae family and is native to subtropical and tropical areas of South America and Central America.
The genus Alternanthera has various popular species, including:
- Alternanthera Ficoidea
- Alternanthera Dentata
- Alternanthera Brasiliana
The common names for Alternanthera include:
- Purple knight
- Joseph’s coat
- Calico weed
- Calico plant
- Little ruby
Joseph’s Coat Care
Size & Growth
This plant grows around 12” inches tall and spreads 12” inches wide, which is a typical growth habit among its species.
The burgundy foliage of this plant remains dense to the ground.
The foliage color ranges from green to burgundy color, but the leaf color is a striking shade of dark purple.
It also has the tendency of arching over containers.
Flowering and Fragrance
The unique feature of the Joseph’s Coat plant is the purple to green leaves instead of its flowers.
The bloom time of the purple knight is short. The white flowers are tiny and formed in axillary and terminal spikes.
It adapts easily to its environment, but work best as annuals as backdrop landscaping, edging, or as a summer bedding plant.
Light & Temperature
Joseph’s Coat Plant thrives best under full sun but also grows well when placed in partial shade.
For intense foliage color, place it under the full sun. The USDA hardiness zones of this plant are 10 – 11.
Watering and Feeding
The Alternanthera plant prefers regular, but light watering.
Make sure to water the plant enough to avoid letting the soil dry out completely.
The new plants need daily watering for the initial weeks.
Watering must be adjusted as per the soil type and weather.
Water lightly for clay soil as they sustain more moisture, but water more in sandy soils as they need increased humidity.
This plant doesn’t require extra fertilizer, as a high amount of feed damages the plant.
However, if your Joseph’s Coat looks week, feed it some balanced liquid food during the summer season.
Soil & Transplanting
The Alternanthera Ficoidea plant is used in most soil types as long as it’s well-draining.
Add in some organic matter, like garden compost, peat moss, or manure to enhance the drainage of the soil.
Grooming and Maintenance
This is a low maintenance plant, as long as it’s growing in well-draining soil in full sunlight.
It’s best to prune this plant to maintain its compact size.
Ideally, grow the plant after the last frost has passed.
When growing Joseph’s Coat in a greenhouse, make sure it stays under full light and is appropriately watered throughout the growing months.
During the winter season, place this plant in a spot with good ventilation and water sparingly.
When growing in a container, make sure to frequently water during the dry, hot season.
Regularly pinching off its growing tips, gives this plant a more neat and formal look.
Be sure to feed it lightly every two months when grown as ground plants, and every two to three weeks when grown as container plants.
How to Propagate Alternanthera
The propagation of the purple knight is done using cuttings or seeds.
When growing it from seeds, it is best to prepare the seeds in germinating mediums for around five weeks before transferring them into the garden.
It is ideal to transplant or transfer the plant outdoors during the night when the temperature consistently stays at 60° degrees Fahrenheit (15° C) or above.
The cuttings should be taken during the late fall season, and root them in a mixture of sand and vermiculite or perlite.
For growing this plant as perennials, it is best to divide its clumps during the spring season.
Alternanthera Pest or Diseases
Most of the issues faced by the purple knight are easily preventable by selecting the right location and soil type.
The plant will develop rot and lose its foliage color when growing in a location which is not well-draining.
Make sure to grow this plant under the full sun, in a well-draining spot for its striking burgundy foliage.
The lankiness and unsightly shape are avoided with regular pruning and pinching during its growing season.
Joseph’s Coat Plant Uses
This plant works well when used as a ground cover, bedding plant, borders, and along pathways and sidewalks.
This makes an excellent houseplant when growing in hanging baskets and containers.
Its striking floorage color adds appeal to any dull corner and adds a bold touch to tabletops, desks, and other such surfaces.
Its unique textured and colored leaves go well with almost every houseplant.