Globe amaranth

Sun

Full sun; flowering is reduced in shade.

Water

Water regularly while establishing, then during prolonged dry spells. Established plants tolerate some drought but flower better with occasional deep watering.

Soil

Well-drained sandy, loamy or gravelly soil; tolerates modest fertility. Avoid waterlogged ground.

Height

1-2 ft (0.3-0.6 m)

Spread

1-1.5 ft (0.3-0.45 m)

Flowers

Summer to the first autumn frost; rounded heads with purple, magenta, pink or white papery bracts surrounding tiny, inconspicuous flowers.

Foliage

Opposite, oval to oblong green leaves with a slightly hairy surface.

Growth

Fast in warm weather.

Care needed

Low

• Pollinators
• Deer resistant
• Drought tolerant
• Heat tolerant
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   1.5 ft (0.45 m)

   full size

Full size in one season.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Fast

• Plant outside only after frost risk has passed and the soil has warmed.
• Space plants about 1-1.5 ft (0.3-0.45 m) apart, allowing air to circulate.
• Water at soil level when the soil becomes dry; avoid keeping it constantly wet.
• Use a light application of balanced fertiliser only if growth is weak; rich feeding encourages leaves rather than flowers.
• Apply a thin mulch after the soil warms, keeping it clear of the stems.

Pruning. Pinch out the growing tips of young plants to encourage branching. During summer, cut flower stems just above a pair of leaves and remove spent heads to keep plants tidy and encourage further bloom.

Early spring

Sow indoors in warmth, about 6-8 weeks before your expected last frost; germination is best around 21-24°C.

Late spring

Harden off seedlings and plant out after frost risk has passed; in warm regions, sow directly into warmed soil.

Early summer

Pinch young plants if needed and water regularly until established.

Summer

Harvest fully coloured, firm flower heads for drying; hang small bunches upside down in a dry, shaded, airy place.

Late summer

Continue cutting flowers and water deeply during extended dry weather.

Autumn

Collect seed from mature, dry heads if wanted, then remove plants after frost kills them.

• Plant in repeated groups near the front or middle of sunny borders for small, rounded accents among looser flowers.
• Combine with zinnias, cosmos and salvias in a summer cutting garden.
• Use compact varieties in sunny containers with trailing plants, ensuring good drainage.
• Mix with fine-textured ornamental grasses in warm, open borders for contrasting flower and foliage shapes.

Garden styles it suits: Cottage garden, Potager (kitchen garden), Pollinator garden, Low-maintenance, Hot border and Small-space.

Plant it with: Zinnias, Cosmos, Mealycup sage, French marigolds, Basil and Dwarf fountain grass.

Wildlife: Flowers provide nectar for butterflies and bees through summer and early autumn.

• Poor flowering or stretched growth: move to full sun and avoid excessive nitrogen feeding.
• Root or stem rot in wet soil: improve drainage, let the soil dry slightly between waterings and remove badly affected plants.
• Powdery mildew: improve spacing and airflow, water at soil level and remove badly affected foliage.
• Aphids on young shoots: rinse off with water; use insecticidal soap if a persistent infestation is damaging growth.

Not known to be toxic to people, cats, dogs or horses. No particular plant part is recognised as poisonous, but animal-specific safety information is limited; do not encourage pets or children to eat it.

• Rio Grande globe amaranth (Gomphrena haageana)

  Usually has narrower leaves and more elongated flower heads, commonly orange or orange-red rather than the rounded purple, pink or white heads typical of globe amaranth.

• Red clover (Trifolium pratense)

  Has leaves divided into three leaflets, often with pale markings; globe amaranth has undivided, opposite leaves and distinctly papery flower heads.

The common name globe amaranth and the species name globosa refer to its rounded flower heads.

Propagation. Usually grown from seed, started indoors before the last frost or sown directly once the soil is warm. Save seed from fully mature, dry heads; named varieties may not come true from saved seed.

Accepted botanical name

Gomphrena globosa

In the US and Canada

Introduced in Hawaii, the lower 48 states, Pacific Basin, Puerto Rico and US Virgin Islands.

Native range

Bolivia, Brazil North, Brazil Northeast, Brazil Southeast, Brazil West-Central, Colombia, Ecuador, Guatemala, Guyana, Honduras, Mexico Gulf and Mexico Northeast.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.