Hummingbird Mint vs Sweet William Plant Comparison

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

Hummingbird Mint

Hummingbird Mint

Agastache spp.

VS
Sweet William

Sweet William

Dianthus barbatus

Hummingbird Mint

Hummingbird Mint

Agastache spp.

Agastache, commonly known as Hummingbird Mint, is a genus of herbaceous perennial plants known for their aromatic foliage and vibrant, nectar-rich flowers. They typically grow between 1 to 5 feet tall, forming bushy clumps. The leaves are usually lance-shaped and toothed. The flowers, which bloom from summer to fall, come in a variety of colors, including purple, pink, orange, and red. Agastache is primarily an outdoor plant, valued for attracting pollinators like hummingbirds and bees to gardens. People grow it for its ornamental value, drought tolerance, and fragrant foliage.

Lamiaceae North America and Asia, depending on species
✨ Features: Attracts hummingbirds and bees, aromatic foliage, drought tolerant
📖 Read Complete Hummingbird Mint Guide
Sweet William

Sweet William

Dianthus barbatus

Sweet William is a popular biennial or short-lived perennial flowering plant, typically grown as an ornamental in gardens. It features clusters of brightly colored, often fragrant flowers in shades of red, pink, white, purple, and bicolors. The plant has a clumping growth habit, reaching heights of 30-60 cm. While it can be grown indoors, it requires very bright light and cool temperatures to thrive, making it primarily an outdoor plant. People grow it for its attractive flowers, fragrance, and ease of cultivation in garden beds and borders.

Caryophyllaceae Southern Europe to Asia
✨ Features: Fragrant flowers, attracts pollinators
📖 Read Complete Sweet William Guide

Quick Plant Comparison

Feature Hummingbird Mint Sweet William
Light Full sun (at least 6 hours of direct sunlight daily) Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering.
Watering Every 7-10 days, depending on weather and soil drainage Every 5-7 days outdoors, less frequently if grown indoors (though indoor growing is not ideal).
Humidity 30-50% 40-60%
Temperature 18-30°C 15-21°C
Care Level Expert Expert
Growth Rate Moderate To Fast Moderate
Max Height 0.3-1 meter (indoors, unlikely to thrive) 30-60 cm (outdoors). Significantly smaller if grown indoors, typically 15-30cm.
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil, such as a sandy or loamy mix. Avoid heavy clay soils. Well-draining, fertile soil. A mix of garden soil, compost, and perlite is suitable.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 10-15 minutes weekly (outdoor) 15 minutes weekly

🔬 Botanical Information — Comparing These Plants

Hummingbird Mint

Scientific Name Agastache spp.
Family Lamiaceae
Native To North America and Asia, depending on species
Also Known As Hummingbird Mint, Anise Hyssop, Giant Hyssop
Leaves The leaves are typically lance-shaped to ovate, with toothed edges. They are usually green or gray-green in color and have a distinct aromatic scent when crushed. The texture can range from smooth to slightly hairy, depending on the species.
Flowers Agastache rarely flowers indoors. Outdoors, it produces abundant flower spikes from summer to fall. The flowers are tubular and come in a variety of colors, including purple, pink, orange, red, and white. They are highly attractive to hummingbirds and bees.

Sweet William

Scientific Name Dianthus barbatus
Family Caryophyllaceae
Native To Southern Europe to Asia
Also Known As Sweet William, Sweet-William
Leaves Lance-shaped, blue-green leaves, 5-10 cm long.
Flowers Flowers are produced in dense clusters (corymbs), 5-10 cm in diameter. Each flower is about 2-3 cm across, with five petals that are often fringed or toothed. Colors range from red, pink, white, purple, and bicolors. Rarely flowers indoors due to light requirements.

📏 Size & Growth — Plant Comparison

Hummingbird Mint

Height 0.3-1 meter (indoors, unlikely to thrive)
Spread 0.3-0.6 meter (can spread via rhizomes, depending on species)
Growth Rate Moderate To Fast
Growth Pattern Agastache typically grows in an upright, bushy habit, forming clumps of foliage and flower spikes. Some species can spread via rhizomes, creating larger colonies over time.

Sweet William

Height 30-60 cm (outdoors). Significantly smaller if grown indoors, typically 15-30cm.
Spread 20-30 cm
Growth Rate Moderate
Growth Pattern Clumping, upright growth habit.

🌱 Propagation — Comparing Plant Growth

Hummingbird Mint

Methods: Seed, stem cuttings, division

Difficulty: Easy To Moderate

Tips: For stem cuttings, take cuttings in spring or early summer and root them in water or well-draining soil. Division is best done in spring or fall.

Sweet William

Methods: Seed, Stem cuttings, Division

Difficulty: Easy

Tips: Sow seeds indoors 6-8 weeks before the last frost or directly outdoors in spring. Stem cuttings can be taken in late spring or early summer. Divide clumps in early spring or fall.

✨ Benefits & Features — Comparing Plant Value

Hummingbird Mint

Agastache is known for its strong aromatic foliage and its ability to attract hummingbirds and other pollinators. The flowers come in a wide range of colors, making it a versatile addition to any garden. Its drought tolerance makes it suitable for xeriscaping.

  • ✓ Attracts pollinators, improving garden biodiversity.
  • ✓ Provides fragrant foliage for sensory enjoyment.
  • ✓ Drought-tolerant, reducing water consumption.
  • ✓ Adds vibrant color to the garden.
  • ✓ Some species have medicinal properties.
  • ⚠️ Toxic to pets

Sweet William

Sweet William is known for its clusters of brightly colored, fragrant flowers. It is a popular choice for cottage gardens and cut flower arrangements.

  • ✓ Attracts pollinators to your garden
  • ✓ Provides fragrant and colorful blooms
  • ✓ Easy to propagate from seed
  • ✓ Adds a touch of cottage charm to your landscape
  • ✓ Can be used in cut flower arrangements
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Hummingbird Mint

Repotting Not applicable for outdoor plants. If grown in containers, repot every 1-2 years, or more frequently if root-bound.
Pruning Deadhead spent flowers to encourage continued blooming. Prune back in late fall or early spring.
Fertilizing Balanced slow-release fertilizer in spring. Avoid over-fertilizing.
Seasonal Care In winter, cut back the plant to the ground after the first frost. In spring, fertilize and provide support if needed. Summer requires regular watering during dry spells.

Sweet William

Repotting Not typically repotted, as it is usually grown as a biennial. If grown in containers, repot in spring if root-bound.
Pruning Deadhead spent flowers regularly to encourage more blooms. Cut back foliage after flowering.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 4-6 weeks during the growing season.
Seasonal Care In spring and summer, provide regular watering and fertilization. Deadhead spent flowers to encourage more blooms. In fall, cut back foliage after flowering. In winter, provide protection from frost in colder climates.

🌞 Light Requirements

Hummingbird Mint

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

Low light tolerant: ❌ No

Sweet William

Full sun to partial shade. Requires at least 6 hours of direct sunlight daily for optimal flowering.

Low light tolerant: ❌ No

💧 Watering Needs

Hummingbird Mint

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, as this can lead to root rot. Signs of underwatering include wilting leaves, while overwatering can cause yellowing leaves and a soggy soil.

Sweet William

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, as this can lead to root rot. Ensure good drainage. Signs of underwatering include wilting leaves, while overwatering can cause yellowing leaves and mushy stems.

🌡️ Temperature & Humidity

Hummingbird Mint

Temperature: 18-30°C

Humidity: 30-50%

Sweet William

Temperature: 15-21°C

Humidity: 40-60%

🤔 Which Plant Is Right For You?

Hummingbird Mint

Hummingbird Mint

Agastache spp.
Care: Expert Time: 10-15 minutes weekly (outdoor) Beginner: No

Experienced gardeners who want to attract pollinators to their outdoor gardens.

✅ Choose This Plant If...

  • You want to attract hummingbirds and bees to your garden.
  • You need a drought-tolerant plant for a sunny location.
  • You appreciate fragrant foliage and colorful flowers.
  • You want a low-maintenance perennial for your garden.
  • You enjoy using herbs in teas or cooking (some species).

❌ Skip This Plant If...

  • You have limited sunlight in your home.
  • You are looking for an easy-to-grow indoor plant.
  • You have pets that might ingest the plant.
📍 Ideal Location: Outdoor garden, sunny border, or container garden in a sunny location.
🎨 Style: Cottage, Naturalistic, Mediterranean
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, plants in the mint family (Lamiaceae) contain essential oils that can cause gastrointestinal upset and dermatitis in dogs, cats, and horses. Symptoms include vomiting, diarrhea, weakness, and skin irritation. The specific toxic compounds vary by species.
Sweet William

Sweet William

Dianthus barbatus
Care: Expert Time: 15 minutes weekly Beginner: No

Gardeners who want colorful, fragrant flowers in their garden beds and borders.

✅ Choose This Plant If...

  • You want a fragrant flower that attracts pollinators.
  • You enjoy cottage garden aesthetics.
  • You want a plant with a variety of flower colors.
  • You are looking for a relatively easy-to-grow garden plant.
  • You want to add cut flowers to your home.

❌ Skip This Plant If...

  • You have pets that might ingest the plant.
  • You don't have a sunny outdoor space.
  • You are looking for a low-maintenance indoor plant.
📍 Ideal Location: Outdoor garden beds, borders, or containers in a sunny location.
🎨 Style: Cottage, Traditional, Bohemian
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Dianthus barbatus is toxic to dogs, cats, and horses. Symptoms include mild gastrointestinal upset and dermatitis. All parts of the plant are considered toxic.

🎯 Quick Verdict

Best for Beginners Neither ideal
Pet Friendly Neither - caution
Less Maintenance Similar effort
Apartment Friendly Check space

⚡ Key Differences Between These Plants

📈

Hummingbird Mint has moderate to fast growth, while Sweet William grows moderate.

💡 Pro Tips For Comparing These Plants

Hummingbird Mint Care Tips

Hummingbird Mint is primarily an outdoor plant and requires full sun to thrive. Growing it indoors is challenging due to its high light requirements and potential for pest infestations. It needs well-draining soil and careful watering to prevent root rot. Indoor growth is often stunted and flowering is unlikely.

  • Plant in well-draining soil to prevent root rot.
  • Provide full sun for optimal flowering.
  • Deadhead spent flowers regularly to encourage more blooms.
  • Water deeply but infrequently, allowing the soil to dry out between waterings.
  • Protect from strong winds, especially taller varieties.
❄️ Winter: In colder climates, cut back the plant to the ground after the first frost. A layer of mulch can help protect the roots from freezing temperatures. Reduce watering significantly during dormancy.
☀️ Summer: Provide regular watering during dry spells. Deadhead spent flowers to encourage continued blooming. Monitor for pests and diseases, and treat as needed. Provide support for taller varieties to prevent them from flopping over.

Sweet William Care Tips

Sweet William is primarily an outdoor plant that requires full sun and well-drained soil. Indoor cultivation is challenging due to the need for intense light and cool temperatures. It is toxic to pets, requiring careful placement. Regular watering and fertilization are essential for healthy growth and flowering.

  • Deadhead spent flowers regularly to encourage more blooms.
  • Provide well-draining soil to prevent root rot.
  • Fertilize regularly during the growing season.
  • Protect from frost in colder climates.
  • Monitor for pests and diseases and treat promptly.
❄️ Winter: In colder climates, provide protection from frost with mulch or move container plants indoors to a cool, bright location. Reduce watering during dormancy.
☀️ Summer: Provide regular watering and fertilization during the growing season. Deadhead spent flowers to encourage more blooms. Protect from intense afternoon sun in hotter climates.

⚠️ Common Problems & Solutions — Plant Care Comparison

Hummingbird Mint

Common Issues: Root rot, powdery mildew, spider mites, aphids
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Powdery mildew: Improve air circulation and apply a fungicide. Spider mites/Aphids: Insecticidal soap or neem oil.

Sweet William

Common Issues: Root rot, Rust, Aphids, Spider mites
Solutions: Root rot: Ensure well-draining soil and avoid overwatering. Rust: Remove infected leaves and apply a fungicide. Aphids: Spray with insecticidal soap. Spider mites: Increase humidity and treat with miticide.

❓ Frequently Asked Questions — Comparing These Plants

Hummingbird Mint

What are the light requirements for Hummingbird Mint?

Hummingbird Mint requires at least six hours of direct sunlight per day to thrive. Choose a location in your garden or on your patio that receives full sun exposure. If growing indoors, place the plant near a sunny window, preferably one facing south or west. Insufficient light can result in weak growth, fewer blooms, and leggy stems. If your plant is not getting enough natural light, consider supplementing with a grow light. Rotate the plant regularly to ensure even light exposure on all sides.

How do I care for Hummingbird Mint?

Hummingbird Mint thrives in full sun and well-draining soil. Water deeply but infrequently, allowing the soil to dry out between waterings. Avoid overwatering, which can lead to root rot. Fertilize lightly in spring with a balanced fertilizer to promote healthy growth and abundant blooms. Deadhead spent flowers regularly to encourage continuous blooming throughout the summer and fall. Prune back the plant in late winter or early spring to remove dead or damaged growth and maintain its shape. Provide good air circulation to prevent fungal diseases. In colder climates, provide winter protection by mulching around the base of the plant.

How do I propagate Hummingbird Mint?

Hummingbird Mint can be propagated through division, stem cuttings, or seed. For division, carefully dig up the plant in spring or fall and divide the root ball into smaller sections, each with healthy roots and shoots. Replant the divisions in well-draining soil. For 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 until they root. Seeds can be sown indoors in early spring or directly outdoors after the last frost.

Sweet William

What are the light requirements for Sweet William?

Sweet William flourishes with plenty of sunlight, ideally needing at least six hours of direct sunlight each day. When grown in shadier conditions, the plant may produce fewer flowers and its stems can become leggy. An east-facing location that provides morning sun and afternoon shade is ideal in hotter climates. In cooler regions, a south-facing location is preferable to ensure sufficient sunlight. If grown indoors, place Sweet William near a sunny window, supplementing with grow lights if necessary, particularly during winter months when natural light is limited. Insufficient light can lead to weak growth and reduced flowering.

How do I care for Sweet William?

Sweet William thrives in well-drained soil and requires full sun to partial shade, ideally at least 6 hours of sunlight daily. Water regularly, especially during dry periods, ensuring the soil remains consistently moist but not waterlogged. Fertilize every 4-6 weeks during the growing season with a balanced, water-soluble fertilizer to promote abundant blooms. Deadhead spent flowers to encourage further flowering. Sweet William prefers cooler temperatures and can tolerate light frost. In warmer climates, provide some afternoon shade to prevent scorching. Protect from strong winds and heavy rain, which can damage the delicate stems and flowers. Mulch around the base of the plant to retain moisture and suppress weeds.

How do I propagate Sweet William?

Sweet William can be propagated through several methods.

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