Golden Giant Amaranth (Amaranthus hybridus)

Plant Snapshot

Common Name: Golden Giant Amaranth
Latin Name: Amaranthus hybridus
Hardiness Zones: Grown as an annual across most temperate regions. Survives only through frost free periods. In colder USDA zones plants die with first hard frost and are grown as annuals. In warmer zones plants may self-seed and act more persistent.
Typical Height: Typically 2–6 ft (60–180 cm) tall for larger 'giant' forms. Smaller plants or selections may be shorter.
Typical Spread: Spreads 1–3 ft (30–90 cm) per plant. Individual plants remain upright but can fill space through branching and self-seeding.
Bloom Period: Blooms from mid summer into fall until frost in most climates.
Soil Preferences: Prefers fertile, well drained soil but tolerates poorer and compacted soils. Avoid waterlogged soils. Neutral to slightly acidic pH is typical but many Amaranthus tolerate a wide pH range.
Light Preferences: Full sun for best foliage color and flowering. Tolerates light afternoon shade but will be less vigorous and shorter in shade.
Toxicity: Many Amaranthus species have edible leaves and seeds for humans but plants can accumulate nitrates and have caused livestock toxicity. Pets may experience mild gastrointestinal upset if eaten and handling may cause minor skin irritation in sensitive individuals.
Propagation: By seed. Sow direct after last frost or start indoors to transplant. Plants self-seed readily.

Key Facts

Warm season annual grown for foliage and seed.
Fast growing and upright in habit.
Propagated easily by seed and often self-seeds.
Performs best in full sun with regular moisture.
Tolerant of a wide range of soils including poorer soils.
Can reach multiple feet in height for 'giant' forms.
Flowers produce abundant small seeds that attract birds.
May accumulate nitrates and pose a livestock risk.

Golden Giant Amaranth (Amaranthus hybridus) is a warm season annual Amaranthus grown for tall upright habit and bright foliage. It grows quickly from seed and sets abundant tiny flowers that produce seed. Plants perform best in full sun and regular moisture and are often allowed to naturalize by self seeding where climates permit.

Identification

Amaranthus hybridus forms upright clumps with broad, often golden tinted leaves and open clusters of small flowers that mature into prolific seedheads. Larger “giant” forms commonly reach about 2 to 6 feet tall depending on selection and growing conditions. Flowering runs from mid summer into fall until frost in most regions.

Best uses

Use Golden Giant Amaranth at the back of mixed borders for vertical color and texture or grow in informal beds where tall annuals are wanted. Leaves and seeds are traditionally used as food in some cultures while flowers attract birds. The plant tolerates poorer soils and can be a low maintenance summer accent with dramatic height.

Planting and timing

Start by seed after the last frost or begin indoors for earlier plants and transplant when the soil has warmed. Space plants roughly 12 to 36 inches apart depending on the cultivar and how dense the planting should be. Expect plants to bloom from summer into fall until they are killed by frost.

Water and soil

Golden Giant prefers fertile, well drained soil and regular moisture for best foliage and flower display. It will tolerate a wide range of soils including poorer or compacted sites but performs poorly in waterlogged ground. Full sun produces the most vigorous growth and richest foliage color while shade results in smaller, leggier plants.

After flowering and seed saving

Allow seedheads to ripen on the plant if you want to save seed or feed birds. Seeds are abundant so watch for natural reseeding. Collect heads before they shatter and dry them indoors if you plan to store seed. Removing seedheads will reduce volunteer seedlings the following season.

Controlling spread

Golden Giant self seeds readily and can naturalize in warm areas where frost is absent. Keep spread in check by deadheading or removing flower spikes before seeds mature and by pulling young volunteers. Mulch and a clean seedbed will limit seedlings in cultivated areas while frequent cutting reduces seed production.

Problems and safety

Amaranthus species are not commonly highly toxic but can accumulate nitrates and have been linked to livestock poisoning under some conditions. Pets that eat foliage may get mild gastrointestinal upset and handling may cause minor skin irritation in sensitive people. Confirm edibility and livestock safety with a local extension before recommending as forage or food.

Frequently asked questions

How fast does Golden Giant Amaranth grow?: This is a fast growing annual that can reach several feet tall within a single warm season when started from seed in full sun and with regular moisture.
When should I sow seeds?: Sow seeds outdoors after the last frost when soils are warm or start indoors to transplant once danger of frost has passed.
Does it self seed?: Yes it self seeds readily and can naturalize where seeds mature and are left to fall into the soil.
Is Golden Giant Amaranth edible?: Some Amaranthus have edible leaves and seeds but nitrate accumulation varies. Verify safety with a regional extension or poison control before consuming or feeding livestock.
How do I prevent too many volunteers?: Remove spent flowerheads before seeds ripen, pull seedlings, and keep beds mulched and weeded to reduce new plants.