Joseph’s coat, which includes several Alternanthera species, is one of those resurgent old garden plants. These are landscape plants with foliage.
As Joseph’s “coat of many colors” is referred to in the Bible, this plant’s colorful foliage makes it an excellent addition to flower gardens.
It performs best when planted in mid-spring (April to May) but can be planted until late summer.
Certain varieties require and thrive in full sun, while others require a partially shaded to the shaded environment to avoid leaf scorch.
Colors of foliage will change in response to changes in sun exposure. Once established, plants are typically not overly reliant on irrigation.
Joseph’s Coat Plant History
Alternanthera, the multicolored Joseph’s coat plant, has a long history in Victorian gardens.
After an extended absence from gardens and houseplant collections, these foliage plants come back but with a twist.
Rather than having leaves in a rainbow of colors, as Joseph’s coat plants of my youth did, many popular new varieties have leaves in just one or two colors.
Because the old name, which referred to a coat of many colors, no longer seems appropriate, the scientific name is frequently used instead of the common name.
Regardless of the name, the plants are easy to grow and vibrant from spring to fall. There’s Partytime, which features red and green foliage, and Red Threads, which features burgundy leaves that are slender and threadlike.
Raspberry Rum is a burgundy color with a fuchsia splash. Green and white is the color of Creme de Menthe. Genuine Yellow is precisely what it is.
Little Ruby is one of my favorites, with deep burgundy leaves and a red backside. The colors remain vibrant even in direct sunlight, and the plant remains compact, growing to a height of less than a foot.
Little Ruby makes an eye-catching sidewalk edging and a vibrant companion plant for flowering plants in containers.
Joseph’s Coat Growing Tips
Joseph’s coat is typically grown in full sun to achieve the most vibrant foliage, but the plants will also tolerate partial shade.
However, with impatiens increasingly threatened by downy mildew, I occasionally see Joseph’s coat recommended as a shade-tolerant impatiens substitute.
It’s probably similar to coleus, with some varieties being more shade-tolerant than others, but I’m still experimenting to determine which types.
It appears that checking plant tags for light requirements is the best course of action for the time being.
I’ve consistently grown Joseph’s coat in well-drained soil as recommended by most sources. However, I went shopping recently for a small bog plant or two to place in a small pot without a drainage hole.
To my surprise, there sat Joseph’s coat among a bog display of notorious water-lovers such as sweet flag and papyrusm.
I chose to give it a shot. I purchased a dwarf sweet flag plant to complement Joseph’s coat’s existing small starter plant.
The two make a lovely pair, and they’re simple to maintain: I fill the pot to the brim with water on occasion.
Thus, I’m curious: Does Joseph’s coat require adequate drainage or not?
As it turns out, there are numerous species, several of which are bog plants.
Many of today’s new varieties are hybrids created by crossing multiple species. It’s difficult to sort out, but give it a try if you need a bog plant.
I am certain of one thing. When the frost is threatened, I take cuttings from any Joseph’s coats I wish to save. Cuttings root easily in water, and the plants thrive in bright light indoors.
- Scientific name: Amaranthus tricolor
- Family: Amaranthaceae
- Common names: Joseph’s coat, tampala, summer poinsettia
- Native to: The tropics, possibly Africa and Indochina
- Description: An herbaceous annual. Leaves are alternate, have an elliptical to ovate shape, and are 4-6 inches in length, 2-4 inches wide.
The leaf color is why the plant is grown as an ornamental. As the plant matures, the upper leaves often are brightly colored shades of fuchsia, hot pink, red, yellow, and green; the lower leaves may be purple, burgundy, green, or variegated.
The flowers are not the star of the show; they are held in clusters in the leaf axils and are very small. The seeds are produced in abundance that can be collected for re-seeding.
- Hardiness: USDA hardiness zones 8-11, damaged by frost.
- Height/width: Grows 1 to 5 feet tall and 2 to 4 feet wide.
- Light: Full sun for best color; however, afternoon shade is beneficial during the hottest part of the day.
- Soil/Moisture: Prefers well-drained soils and is very drought-tolerant.
- Culture/uses: Joseph’s coat is planted for its attention-getting leaves and excellent heat tolerance.
Plant it in masses to draw interest in any area, such as at the back of beds, borders, and containers. It is annual to grow from seed to seed in a year.
Due to its short-day nature, it tends to flower, go to seed, and decline in the fall. Joseph’s coat will have to be replanted or allowed to regrow from seeds every year.
The best time to plant the seed along the Treasure Coast is January through April. Protect the seedlings and plants from frost. Mulch well to suppress weeds.
Fertilize only if necessary; excess fertilizer or rich soils suppress the brilliant leaf color. Water sparingly. Pruning usually is unnecessary, but the plants may require staking to remain upright.
- Misuses and notes: Joseph’s coat is susceptible to root rot and fungal leaf spot in wet or over irrigated soil.
It is susceptible to infestation from aphids and caterpillars; however, control only if the damage is excessive and beneficial insects are not present.
Any part of this plant is eatable and is popular as a summer alternative to spinach.
Use caution if harvesting landscape plants for consumption; pesticides used on landscape ornamentals may not be labeled for use on vegetable plants and may be dangerous to consume.