Globe Amaranth vs Grevillea Plant Comparison

Compare these two plants side by side — care needs, key differences, and which is right for your home.

Globe Amaranth

Globe Amaranth

Gomphrena globosa

VS
Grevillea

Grevillea

Grevillea spp.

Globe Amaranth

Globe Amaranth

Gomphrena globosa

Globe Amaranth is an annual flowering plant known for its globe-shaped flower heads that come in various colors, including purple, pink, red, orange, and white. Typically grown outdoors, it reaches a height of 1-2 feet. The plant has an upright growth habit with oval-shaped leaves. People grow it for its long-lasting blooms, which are excellent for fresh and dried flower arrangements. It thrives in warm weather and full sun, making it a popular choice for summer gardens. While technically possible to grow indoors, it requires very bright light and consistent care to mimic its natural outdoor environment.

Amaranthaceae Central America (Panama, Guatemala)
✨ Features: Excellent for cut flowers and dried flower arrangements.
📖 Read Complete Globe Amaranth Guide
Grevillea

Grevillea

Grevillea spp.

Grevilleas are a diverse genus of evergreen trees and shrubs, ranging in size from groundcovers to large trees. They are known for their distinctive, often spider-like flowers that come in a variety of colors, including red, pink, orange, yellow, and white. Most Grevilleas are outdoor plants, prized for their drought tolerance and ability to attract birds and insects. Indoor cultivation is challenging due to their high light requirements and need for excellent drainage. People grow them for their unique flowers, foliage, and wildlife attraction.

Proteaceae Australia, New Guinea, New Caledonia, Sulawesi
✨ Features: Attracts birds and insects, unique flower shapes, drought tolerance (outdoors)
📖 Read Complete Grevillea Guide

Quick Plant Comparison

Feature Globe Amaranth Grevillea
Light Full sun (at least 6-8 hours of direct sunlight daily) Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours per day.
Watering Every 2-3 days outdoors during hot weather; less frequently indoors (every 5-7 days) depending on light and temperature. Every 1-2 weeks indoors, depending on light and temperature. Less frequent watering outdoors once established.
Humidity 40-60% 30-50%
Temperature 21-27°C 15-25°C
Care Level Expert Expert
Growth Rate Moderate Moderate To Fast, Depending On The Species And Growing Conditions.
Max Height 0.3-0.6 meters (indoors, typically smaller) Indoors: 1-2 meters (if successfully grown). Outdoors: Varies greatly by species, from groundcovers to 30+ meter trees.
Pet Safety ✅ Safe ❌ Toxic To Pets
Soil Well-draining soil mix, such as a blend of potting soil, perlite, and sand. Well-draining, slightly acidic soil. A mix of potting mix, sand, and perlite is suitable.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 15 minutes weekly 30 minutes weekly

🔬 Botanical Information — Comparing These Plants

Globe Amaranth

Scientific Name Gomphrena globosa
Family Amaranthaceae
Native To Central America (Panama, Guatemala)
Also Known As Globe Amaranth, Bachelor Button
Leaves Oval to lance-shaped leaves, typically 2-4 inches long. They are usually green but can have a slightly reddish tinge. The leaves have a slightly rough texture.
Flowers Flowers profusely outdoors in summer and fall. The flower heads are globe-shaped and come in various colors, including purple, pink, red, orange, and white. Indoor flowering is rare and requires ideal conditions.

Grevillea

Scientific Name Grevillea spp.
Family Proteaceae
Native To Australia, New Guinea, New Caledonia, Sulawesi
Also Known As Grevillea, Spider Flower, Silky Oak (for some species)
Leaves Leaves vary greatly by species, ranging from needle-like to broad and lobed. They are typically evergreen and can be green, grey-green, or bronze. Some species have silky hairs on their leaves.
Flowers Grevilleas rarely flower indoors due to the lack of sufficient light and humidity. Outdoors, they produce distinctive spider-like flowers in a variety of colors, including red, pink, orange, yellow, and white. The flowers are rich in nectar and attract birds and insects.

📏 Size & Growth — Plant Comparison

Globe Amaranth

Height 0.3-0.6 meters (indoors, typically smaller)
Spread 0.2-0.3 meters
Growth Rate Moderate
Growth Pattern Upright, bushy growth habit, typically reaching 1-2 feet in height. It produces numerous stems with oval-shaped leaves and globe-shaped flower heads at the tips of the stems.

Grevillea

Height Indoors: 1-2 meters (if successfully grown). Outdoors: Varies greatly by species, from groundcovers to 30+ meter trees.
Spread Indoors: 0.5-1 meter. Outdoors: Varies greatly by species.
Growth Rate Moderate To Fast, Depending On The Species And Growing Conditions.
Growth Pattern Varies greatly by species. Some are groundcovers, others are shrubs, and some are trees. Indoors, they tend to be more upright and shrub-like.

🌱 Propagation — Comparing Plant Growth

Globe Amaranth

Methods: Seed

Difficulty: Easy

Tips: Sow seeds indoors 6-8 weeks before the last expected frost or directly outdoors after the danger of frost has passed. Keep the soil consistently moist until germination.

Grevillea

Methods: Seed, stem cuttings, grafting

Difficulty: Moderate To Difficult

Tips: Take semi-hardwood cuttings in late spring or early summer. Use rooting hormone and provide bottom heat. Seeds require pre-treatment, such as scarification or soaking.

✨ Benefits & Features — Comparing Plant Value

Globe Amaranth

Globe Amaranth's unique globe-shaped flowers retain their color and shape even when dried, making them ideal for crafts and dried flower arrangements. Unlike many annuals, it continues to bloom profusely throughout the summer with regular deadheading.

  • ✓ Provides vibrant color to gardens and floral arrangements.
  • ✓ Attracts pollinators like butterflies and bees.
  • ✓ Flowers are excellent for drying and crafting.
  • ✓ Relatively low-maintenance once established outdoors.
  • ✓ Can be grown in containers for smaller spaces.
  • 🐾 Pet Safe

Grevillea

Grevilleas are known for their distinctive, spider-like flowers and often intricate foliage. Their flowers attract a variety of birds and insects, making them a valuable addition to any garden. The diverse range of species allows for a variety of sizes and growth habits.

  • ✓ Unique and interesting foliage and flowers.
  • ✓ Attracts birds and beneficial insects (outdoors).
  • ✓ Adds a touch of the Australian landscape to your home.
  • ✓ Can be a conversation starter due to its unusual appearance.
  • ✓ Offers a rewarding challenge for experienced plant enthusiasts.
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Globe Amaranth

Repotting Not applicable as it's an annual plant.
Pruning Deadhead spent flowers to encourage continuous blooming.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 2-4 weeks during the growing season.
Seasonal Care In spring, start seeds indoors or outdoors. In summer, provide consistent watering and fertilization. In fall, harvest flowers for drying. Globe Amaranth is an annual and will not survive winter in cold climates.

Grevillea

Repotting Every 1-2 years, or when the plant becomes root-bound. Use a well-draining potting mix.
Pruning Prune regularly to maintain shape and encourage bushier growth. Prune after flowering.
Fertilizing Low-phosphorus fertilizer, diluted to half strength, every 2-3 months during the growing season (spring and summer). Avoid high-phosphorus fertilizers.
Seasonal Care Reduce watering in winter. Provide supplemental light if needed. Increase watering and fertilizing during the growing season (spring and summer).

🌞 Light Requirements

Globe Amaranth

Full sun (at least 6-8 hours of direct sunlight daily)

Low light tolerant: ❌ No

Grevillea

Full sun to partial shade outdoors. Indoors, requires very bright, direct light for at least 6 hours per day.

Low light tolerant: ❌ No

💧 Watering Needs

Globe Amaranth

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. Allow the soil to drain well after watering. Signs of underwatering include wilting leaves and dry flower heads. Overwatering can cause yellowing leaves and a mushy stem.

Grevillea

Allow the soil to dry out slightly between waterings. Overwatering can lead to root rot. Check soil moisture regularly. Outdoors, established plants are drought-tolerant. Indoors, water thoroughly when the top inch of soil is dry. Signs of overwatering include yellowing leaves and soggy soil. Underwatering results in wilting and dry, crispy leaves.

🌡️ Temperature & Humidity

Globe Amaranth

Temperature: 21-27°C

Humidity: 40-60%

Grevillea

Temperature: 15-25°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Globe Amaranth

Globe Amaranth

Gomphrena globosa
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners who want colorful, long-lasting blooms for fresh or dried flower arrangements in a sunny outdoor space.

✅ Choose This Plant If...

  • You want vibrant, globe-shaped flowers in your garden.
  • You need flowers that are excellent for drying and crafting.
  • You have a sunny outdoor space with well-draining soil.
  • You want to attract pollinators like butterflies and bees to your garden.
  • You want a low-maintenance annual flower once established.

❌ Skip This Plant If...

  • You don't have a location with full sun (at least 6 hours daily).
  • You are looking for a low-maintenance indoor plant.
  • You live in a climate with consistently cool or wet summers.
📍 Ideal Location: Sunny garden bed or container outdoors.
🎨 Style: Cottage, Bohemian, Traditional
🏠 Apartment Friendly: Limited
⚠️ According to the ASPCA, Globe Amaranth is not listed as toxic to dogs, cats, or horses.
Grevillea

Grevillea

Grevillea spp.
Care: Expert Time: 30 minutes weekly Beginner: No

Experienced gardeners who want to try a challenging plant indoors or those with suitable outdoor climates.

✅ Choose This Plant If...

  • You have a very sunny indoor location and are willing to provide supplemental light.
  • You are an experienced gardener looking for a challenging plant to grow indoors.
  • You want to attract birds to your outdoor garden (if planting outdoors).
  • You appreciate unique and unusual flower shapes.
  • You are willing to provide well-draining soil and avoid overwatering.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You have limited sunlight indoors.
  • You are a beginner gardener looking for an easy-to-care-for plant.
📍 Ideal Location: Outdoors in a sunny location. Indoors, a south-facing window with supplemental lighting.
🎨 Style: Modern, Australian Native, Eclectic
🏠 Apartment Friendly: Limited
⚠️ Grevillea species contain cyanogenic glycosides. These can cause cyanide poisoning, especially in dogs, cats, and horses. Symptoms include vomiting, diarrhea, lethargy, and difficulty breathing. All parts of the plant are considered toxic.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Globe Amaranth ✓
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

📈

Globe Amaranth has moderate growth, while Grevillea grows moderate to fast, depending on the species and growing conditions..

💡 Pro Tips For Comparing These Plants

Globe Amaranth Care Tips

Globe Amaranth is primarily an outdoor plant that requires full sun and well-draining soil. Indoor cultivation is challenging due to the high light requirements. Consistent watering and fertilization are necessary for healthy growth and abundant blooms. Proper ventilation is crucial to prevent fungal diseases.

  • Provide full sun for optimal flowering.
  • Water deeply but infrequently, allowing the soil to dry slightly between waterings.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Fertilize every 2-4 weeks with a balanced liquid fertilizer.
  • Protect from strong winds, which can damage the stems.
❄️ Winter: Globe Amaranth is an annual and does not survive winter in cold climates. Collect seeds for planting the following spring.
☀️ Summer: Provide consistent watering, especially during hot and dry periods. Fertilize regularly to promote continuous blooming. Deadhead spent flowers to encourage more blooms.

Grevillea Care Tips

Grevilleas are primarily outdoor plants and are challenging to grow indoors. They require very bright light, excellent drainage, and careful watering to avoid root rot. Maintaining appropriate humidity and temperature can also be difficult. Regular pruning is necessary to maintain shape.

  • Provide excellent drainage to prevent root rot.
  • Use a low-phosphorus fertilizer.
  • Prune regularly to maintain shape and encourage bushier growth.
  • Ensure adequate air circulation to prevent fungal diseases.
  • Monitor for pests and treat promptly.
❄️ Winter: Reduce watering frequency. Provide supplemental light if needed. Protect from frost if grown outdoors in marginal climates.
☀️ Summer: Increase watering frequency. Provide some shade during the hottest part of the day if grown outdoors in very hot climates. Fertilize regularly during the growing season.

⚠️ Common Problems & Solutions — Plant Care Comparison

Globe Amaranth

Common Issues: Powdery mildew, root rot, aphids
Solutions: Powdery mildew: Improve air circulation and apply a fungicide. Root rot: Ensure well-draining soil and avoid overwatering. Aphids: Spray with insecticidal soap or neem oil.

Grevillea

Common Issues: Root rot, spider mites, scale, nutrient deficiencies (especially iron)
Solutions: Root rot: Improve drainage, reduce watering frequency. Spider mites: Increase humidity, spray with insecticidal soap. Scale: Remove manually, treat with horticultural oil. Nutrient deficiencies: Use a balanced fertilizer with micronutrients.

❓ Frequently Asked Questions — Comparing These Plants

Globe Amaranth

What are the light requirements for Globe Amaranth?

Globe Amaranth requires ample sunlight to thrive and produce abundant blooms. Aim for at least 6-8 hours of direct sunlight per day. A south-facing location is ideal, providing the most intense sunlight. If growing indoors, place the plant near a sunny window or supplement with grow lights. Insufficient light can result in leggy growth, fewer flowers, and duller colors. Rotate the plant regularly to ensure even light exposure on all sides. Plants grown in partial shade may still survive, but their flowering will be significantly reduced. Consider the intensity of the sun in your region, providing some afternoon shade in extremely hot climates to prevent scorching.

How do I care for Globe Amaranth?

Globe Amaranth is relatively easy to care for, thriving in warm, sunny conditions. Plant in well-draining soil that is moderately fertile. Water regularly, especially during dry periods, but avoid overwatering, which can lead to root rot. Fertilize every 4-6 weeks with a balanced fertilizer during the growing season to encourage abundant blooms. Deadhead spent flowers to promote continuous flowering. Provide full sun, ideally 6-8 hours per day. Protect from frost, as Globe Amaranth is sensitive to cold temperatures. Space plants adequately to allow for good air circulation. Monitor for pests such as aphids or spider mites and treat accordingly. Prune lightly to maintain shape and encourage branching. Avoid overhead watering to prevent fungal diseases.

How do I propagate Globe Amaranth?

Globe Amaranth is easily propagated from seed. Sow seeds indoors 6-8 weeks before the last frost or directly outdoors after the danger of frost has passed. For stem cuttings, take a 4-6 inch cutting from a healthy plant, remove the lower leaves, and dip the cut end in rooting hormone. Plant the cutting in moist potting mix and keep it humid until roots develop. Division is not typically used for Globe Amaranth. Keep soil moist but not soggy. Place in a warm, sunny location. Seedlings should emerge in 7-14 days. Transplant seedlings into individual pots once they are large enough to handle. Harden off seedlings before transplanting them outdoors.

Grevillea

What are the light requirements for Grevillea?

Grevilleas thrive in bright, direct sunlight for at least six hours each day. Insufficient light can lead to leggy growth, reduced flowering, and weakened plants. When grown indoors, place Grevilleas near a south-facing window or under grow lights to ensure adequate light exposure. Rotate the plant regularly to promote even growth on all sides. If leaves start to turn pale or yellow, it may indicate that the plant is receiving too much direct sunlight, especially during the hottest part of the day. Filtered light or partial shade during peak hours can help prevent leaf burn. Outdoor-grown Grevilleas should be planted in a location that receives full sun for most of the day.

How do I care for Grevillea?

Grevilleas require well-draining soil, ideally a sandy or gravelly loam. Water thoroughly when the top inch of soil is dry, allowing excess water to drain away. Avoid overwatering, which can lead to root rot. Provide at least 6 hours of direct sunlight daily for optimal flowering. Fertilize sparingly with a low-phosphorus fertilizer specifically formulated for native plants during the growing season (spring and summer). Prune lightly after flowering to maintain shape and encourage bushier growth. Protect from frost in colder climates. Monitor for pests such as aphids and scale, and treat as needed. Ensure good air circulation to prevent fungal diseases. Repot young plants annually in spring, using a slightly larger pot each time. Mature plants can be repotted every 2-3 years. Maintaining a slightly acidic soil pH is beneficial.

How do I propagate Grevillea?

Grevilleas can be propagated through stem cuttings. Take 4-6 inch cuttings from new growth in spring or summer. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in a well-draining potting mix and keep them moist in a warm, humid environment. Rooting typically takes several weeks. Another method is seed propagation, although it can be more challenging. Collect seeds from mature seed pods and sow them in a well-draining seed starting mix. Keep the soil moist and warm until germination occurs. Division is possible for some clumping varieties. Carefully separate the plant at the roots and plant each section in its own pot.

Last updated: May 6, 2026 — Plant care data reviewed and verified by our editorial team.