How to Plant, Grow, and Care For Globe Amaranth
Are you looking for some new flowers to brighten up your garden bed? Globe Amaranth may be just the trick! These beautiful flowers can liven up any garden space, but they do have a few needs to satisfy before you'll get a perfect bloom. In this article, gardening and flower expert Taylor Sievers examines how to plant, grow, and care for Globe Amaranth.
Are you looking for a plant for a sunny spot in your garden that will provide both fun color and texture? Are your plant husbandry skills lacking in more ways than one? Well, look no further than globe amaranth!
Globe amaranth, also called gomphrena, is a heat-loving plant native to the southern United States, Mexico, Guatemala, and Panama, depending on which of the two clover look-alike species we’re talking about. Gomphrena globosa and Gomphrena haageana flowers both have a cute, globe-shaped flower (botanically speaking, colored “bracts”) atop long, mostly bare stems, but you’ll find that G. haageana has narrower, fuzzy leaves compared to its sister G. globosa. However, both species make excellent fresh cut and dried flowers!
This lovely flowering plant has very few pest and disease issues and comes in all sorts of colors like white, pink, carmine, purple, orange, and red. They’re slow to start in the Spring, but when the Summer heat begins to kick in these plants will be off to the races! Cut the little, papery globes to put in a vase on your dining room table or dry them to use in Fall and Winter wreaths. Once they get going in the garden or in your patio pot, you won’t be disappointed!
Globe Amaranth Plant Overview
Species Globosa, Haageana
Soil Type Well-draining
Plant With Lantana, Salvia, Marigolds
Don’t Plant With Cool Climate Plants
Plant Type Annual
Native Area Central America
Hardiness Zone USDA 9-11
Exposure Full Sun
Maturity Date 85-100 Days
Growth Rate Moderate to Slow
Plant Spacing 8-18 inches
Plant Depth 1/8 inch
Height 1-2 feet
Watering Requirements Low
Pests and Diseases Low Risk
Tolerance Warm Climates
Plant History and Cultivation
Globe amaranth is native to Central America and South America, though the plant has been grown in European and American gardens for hundreds of years. G. globosa is said to have originated in Central America in the areas between Guatemala and Panama, while G. haageana is considered a native tender perennial of Texas, New Mexico, and northern Mexico.
In 1714, this flower was introduced to European gardens and by 1737 had made its way to Virginia in the garden of John Custis. On April 2, 1767, Thomas Jefferson was reported to have planted it at his boyhood home in Shadwell. Today, this flower is still grown at Monticello and is said to be the most asked about the plant on the property today.
Today, gomphrena proves a fun addition as a landscape plant and is excellent as a cut flower for fresh and dried arrangements.
Globe amaranth is propagated by seed, and can be sown directly in the garden or started early indoors. Starting seed indoors is the recommended way to propagate gomphrena due to its slow germination.
A tip for starting seeds is to soak the seeds prior to planting to promote faster germination, though this method is not necessary. Soak the seeds for 1 to 2 days in water. Seedlings can be very slow to germinate, so patience is key.
Starting Gomphrena Seed Indoors
Globe amaranth seeds should be started at least 6 to 8 weeks prior to your last estimated frost. To start seeds indoors, you’ll need a few supplies to get started. Seed-starting trays can be purchased from hardware stores in early Spring, but any pot or container will work.
Small plastic or paper cups with holes poked in the bottom could also be used to start seeds indoors. Fill the trays or pots with a seed-starting mix and lightly tamp it down to make sure the cells or pots are full. These seed-starting mixes are usually peat or coconut-coir-based and are light and airy to promote excellent seedling root development.
Using a dibble or even the tip of a pencil, poke holes in the top of the seed-starting mix for your seeds. Drop your seeds into each hole. Some people drop two seeds per hole and thin out the seedlings later just in case one of the seeds doesn’t germinate.
Gomphrena prefers to be planted at about an ⅛ inch depth, so make sure you don’t make your holes too deep. Pinch the seed-starting mix closed. It is best to bottom water to avoid damaging your small seedlings. Placing the pots or propagation trays on a dish or in a solid flat tray will allow you to bottom water by pouring water into the dish.
The water will be wicked up by the seed-starting mix through the drainage holes or your pot or cell tray and thus keep your seedlings moist. To avoid moisture loss while the seeds are germinating, cover the tray or your pots with either plastic Saran wrap, a clear plastic dome lid, or even the top of a plastic milk jug or water bottle.
Starting By Seed in the Garden
This plant can be sowed directly into the garden or landscape after your last estimated frost. Bury the seed at least ⅛ inch into the soil. This can be accomplished by broadcasting the seeds into the area you want to plant them and gently raking them into the soil and watering the area well to jumpstart germination.
Note that this flower can have sporadic germination and is a very slow grower during the seedling stage. This is why it is best to start them indoors where factors such as moisture, light, and heat can be controlled. Do not fret, however! Once exposed to the warmth of early Summer, your new flowers will be off to the races!
How to Grow
Globe amaranth prefers moderately moist soil in full sun (6-8+ hours of direct sunlight). Once established, gomphrena can tolerate drier soils. The plants are fairly low maintenance once established.
Plant transplants 6 to 8 inches apart to promote long, strong stems for cutting or plant 12 to 18 inches apart in the landscape. Be aware that planting as far as 18 inches apart for varieties that are larger is great for air circulation, but the plants may need extra support if planted too far apart.
It is highly recommended to pinch seedlings when they are about 6 inches tall. Pinch just above a set of leaves. This will promote the branching of your plants, which means a fuller plant with more globe-like flowers!
Gomphrena thrives the more you cut. You can cut the flower stems just above a set of leaves deep into the plant periodically to keep the plant blooming all Summer into the Fall. The plant will continue to branch and put out new flower heads as long as you keep it maintained, otherwise the colorful bracts will begin to fade and the flowers will give way to seed.
Sow or transplant gomphrena into mass plantings in the landscape or in containers. These plants are highly adapted for both applications. Choosing companion flowers with complementing colors will provide for a striking impact in your garden.
Some examples of pairings would be purple varieties of globe amaranth with the sunset-colored lantana or marigolds. Dark-colored sweet potato vines contrast nicely with pink or rose-colored globes. White or pastel pink shades of these flowers are beautiful with blue annual salvias or lavender ageratum.
When and How to Harvest
The true flowers of gomphrena are actually rather inconspicuous whitish-yellow flowers. The colorful part of the “globe” is made up of several bracts (modified leaves or scales with a flower at its axil).
If you look closely, you will be able to see the tiny flowers begin to open from the bottom of the flower head to the top. If cutting gomphrena for fresh use in a flower arrangement, it is best to wait until the little inconspicuous flowers begin to open. Usually, at this time, the neck of the stem has become stronger so the globed flower will not droop when in a vase.
Globe amaranth flowers can be used for fresh or dried use. To dry gomphrena, strip the leaves and bundle several stems to hang upside down in a warm, dry, and well-ventilated place with low light. They have remarkable retention of color after drying and will last indefinitely.
To collect their seeds, wait until the flowers have faded and begun to dry. Cut the flower heads or whole stems off the plant. Crush the globe gently within your hand to loosen the seeds and remove the colorful, papery husks (bracts). Store the seeds in a paper bag in a cool, dark place until you’re ready to plant.
If you’re saving your own seeds, note that hybrid plants will not produce true-to-type seed. What does true-to-type mean?
Hybrids are crosses between two parents of unique genetic origin. The resulting cross usually produces a more vigorous plant with strong, desirable traits (this phenomenon can be described as hybrid vigor). However, the seeds produced from hybrid plants contain a variety of genes that may not have been expressed physically in the hybrid plant.
In the progeny of the hybrid plant, however, you may see this variance in genes that come from the grandparent plants expressed physically in each offspring plant. For example, one seed may produce a tall, red flower with fuzzy leaves and the other may be short and purple-flowered with mostly hairless leaves.
Some varieties of this plant are open-pollinated, meaning that, for the most part, their seed will be true-to-type. For example, if you save seed from an open-pollinated purple variety, then it will likely have the same characteristics as the mother plant. This is only the case as long as there weren’t other globe amaranth plants nearby that could have crossed with your mother plant.
If you love surprises, then saving your own gomphrena seed may be the way to go! You can find out if your variety is a hybrid or open-pollinated by studying your seed company’s catalog or website.
There are several popular varieties of this particular flower. Figuring out which variety is best for your garden will depend on a variety of different factors, including your hardiness zone, soil type, and what the climate is like where you live. Let’s look at the most popular varieties.
This species usually reaches about 12 to 24 inches in height. ‘QIS’ series offers several colors as well as a mix that makes great cut flowers. Colors include white, purple, lilac, carmine, rose, and red.
Bicolor Rose offers a unique fading of white into rose color. Gnome series is only 6 inches tall and comes in pink, purple, and white. Fireworks is a newer, wispier form of gomphrena with a much looser look to the hot pink bracts. These plants are much taller than other varieties with an average height of 3 to 4 feet.
This species tends to sprawl if not planted closer together but will reach, on average, 12 to 18 inches in height. ‘Strawberry Fields’ is a beautiful variety with strawberry red bracts and is very prolific. This species also has a ‘QIS’ series known for its excellent cutting quality with colors of orange, carmine, and red.
In general, globe amaranth does not have many pest problems, but they are susceptible to powdery mildew, gray mold, and fungal leaf spots in cool, damp conditions.
To avoid disease, make sure your plants are planted in full sun in well-draining soil. Water overhead can also cause disease problems, so make sure to water at the base of your plant. These plants are deer resistant and will attract butterflies to your garden or patio.
Globe amaranth makes an excellent cut flower! Simply harvest the flower at the peak time of color and strip the leaves from the plant. Gather stems into a loose bundle and tie them together with either a rubber band or some twine, and then hang the bundle upside down to dry for 2 to 3 weeks.
It is best to dry this plant in a warm, dry place with low light to reduce fading of color. These dried flowers will last indefinitely! Use them in wreaths, potpourri, flower crowns, or dried flower bouquets.
Globe amaranth can be used as a fresh or dried cut flower in flower arrangements or wreaths. Plant a dwarf variety in a patio pot as a filler or even along a border. Gomphrena is exceptionally tolerant of hot, dry conditions so it would be a great rock garden candidate.
In folk medicine, G. globosa has been used as a treatment for high blood pressure and other diseases. One study by Arcanjo et al (2011) confirmed this plant’s use as an antihypertensive.
Some people use the flowers to make a tea or combine them with other herbs in a poultice or lotion due to gomphrena’s supposed antimicrobial and anti-inflammatory properties. In Indian herbal medicine, this plant has traditionally been used to treat “stoppage of water,” also known as urinary retention.
Frequently Asked Questions
Does globe amaranth need full sun?
Yes. This plant is native to the southern part of the United States, Mexico, Central America, and South America, so this plant will thrive in warm, dry conditions with full sun. In fact, if planted as a transplant in the garden in late Spring when conditions are still quite cool, you may notice that it will take your gomphrena a while to grow. Don’t fear. Once the Summer heat arrives, your flowers will thrive!
Should I deadhead my globe amaranth?
Yes, you should deadhead your globe amaranth as the flowers begin to fade. This will keep your plant tidy and will also promote more blooms! Cut the flower at the base of its stem just above a leaf node or at the axil of another flower stem to remove it. Don’t be afraid to deadhead! It will take a lot to hurt this hardy plant.
Does globe amaranth reseed?
In some cases, this plant can reseed itself, but it is rarely a problem if it does reseed. However, in Costa Rica, Cuba, and Hawaii, which indicates that aggressive takeover may only be an issue in warmer regions.
Globe amaranth is an excellent choice if you’re looking for a plant that is tolerant of hot, dry conditions and full sun. The globe-shaped flowers are simply adorable in the landscape or in fresh and dried flower arrangements! This plant may be a little tricky to get started at first, but once it establishes in your garden it’ll be one of the toughest plants. Don’t miss out on these cute little colorful globes this gardening season!