Black-Eyed Susan vs Bugloss Plant Comparison

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

Black-Eyed Susan

Black-Eyed Susan

Rudbeckia hirta

VS
Bugloss

Bugloss

Anchusa azurea

Black-Eyed Susan

Black-Eyed Susan

Rudbeckia hirta

Rudbeckia hirta, commonly known as Black-Eyed Susan, is a flowering plant typically grown as an annual or short-lived perennial. It features daisy-like flowers with bright yellow petals surrounding a dark brown or black central cone. The plant grows upright, reaching heights of 1 to 3 feet. It is primarily an outdoor plant, valued for its vibrant blooms and ability to attract pollinators to gardens. While technically possible to grow indoors, it requires very specific and intense lighting conditions to thrive and bloom, making it challenging.

Asteraceae Eastern and Central North America
✨ Features: Attracts butterflies and bees, deer resistant, long blooming period.
📖 Read Complete Black-Eyed Susan Guide
Bugloss

Bugloss

Anchusa azurea

Anchusa azurea, commonly known as Large Blue Alkanet, is a herbaceous perennial primarily grown outdoors for its vibrant blue flowers. It features coarse, hairy leaves and an upright, branching habit. Typically reaching heights of 3-5 feet, it's a robust plant that thrives in sunny locations. While admired for its striking blooms that attract pollinators, it's not typically grown indoors due to its size, light requirements, and potential for aggressive spread via rhizomes.

Boraginaceae Europe, Western Asia
✨ Features: Attracts pollinators, vibrant blue flowers
📖 Read Complete Bugloss Guide

Quick Plant Comparison

Feature Black-Eyed Susan Bugloss
Light Full sun (at least 6-8 hours of direct sunlight daily) Full sun (at least 6 hours of direct sunlight per day)
Watering Outdoors: Every 3-7 days depending on weather. Indoors (not recommended): Possibly more frequent, but monitor soil moisture carefully. Every 7-10 days during the growing season, less frequently in winter.
Humidity 30-50% 30-50%
Temperature 18-27°C 15-25°C
Care Level Expert Expert
Growth Rate Moderate Fast
Max Height Outdoors: 30-90 cm. Indoors (unlikely): Significantly smaller, if it survives. N/A (Outdoor plant, not suited for indoor growing)
Pet Safety ❌ Toxic To Pets ❌ Toxic To Pets
Soil Well-draining soil, such as a mix of potting soil, perlite, and sand. Well-drained soil, tolerates a range of soil types including sandy and loamy soils.
Beginner Friendly ❌ No ❌ No
Weekly Maintenance 5-10 minutes weekly (deadheading) 15 minutes weekly during the growing season.

🔬 Botanical Information — Comparing These Plants

Black-Eyed Susan

Scientific Name Rudbeckia hirta
Family Asteraceae
Native To Eastern and Central North America
Also Known As Black-Eyed Susan, Brown-Eyed Susan, Gloriosa Daisy
Leaves The leaves are lance-shaped, rough in texture, and medium green in color. They are typically 2-6 inches long and arranged alternately along the stem.
Flowers Flowers are daisy-like with bright yellow petals surrounding a dark brown or black central cone. They bloom profusely throughout the summer and into the fall.

Bugloss

Scientific Name Anchusa azurea
Family Boraginaceae
Native To Europe, Western Asia
Also Known As Large Blue Alkanet, Garden Anchusa, Italian Bugloss, Blue Bugloss
Leaves Large, lance-shaped, and hairy leaves with a rough texture. Typically a medium to dark green color.
Flowers Produces clusters of vibrant blue, five-petaled flowers in spring and summer. The flowers are small but numerous, creating a striking display.

📏 Size & Growth — Plant Comparison

Black-Eyed Susan

Height Outdoors: 30-90 cm. Indoors (unlikely): Significantly smaller, if it survives.
Spread 30-60 cm
Growth Rate Moderate
Growth Pattern Upright, bushy growth habit. It forms clumps that can spread over time, but it is not considered aggressively invasive.

Bugloss

Height N/A (Outdoor plant, not suited for indoor growing)
Spread N/A (Outdoor plant, spreads via rhizomes)
Growth Rate Fast
Growth Pattern Upright, branching habit, forming a clump of coarse, hairy foliage. Spreads via rhizomes, potentially becoming invasive in some situations.

🌱 Propagation — Comparing Plant Growth

Black-Eyed Susan

Methods: Seed, Division

Difficulty: Easy

Tips: For seeds, sow directly into the garden in spring or start indoors 6-8 weeks before the last frost. For division, divide clumps in early spring or fall.

Bugloss

Methods: Seed, Root cuttings, Division

Difficulty: Moderate

Tips: Sow seeds in spring or fall. Root cuttings can be taken in late fall or early spring. Divide established clumps in early spring or fall.

✨ Benefits & Features — Comparing Plant Value

Black-Eyed Susan

The dark central cone provides a striking contrast to the bright yellow petals. It's a popular choice for attracting pollinators and is relatively deer-resistant.

  • ✓ Attracts pollinators
  • ✓ Adds vibrant color to gardens
  • ✓ Deer resistant
  • ✓ Relatively low maintenance outdoors
  • ✓ Native plant supports local ecosystems
  • ⚠️ Toxic to pets

Bugloss

The intense blue color of the flowers is a standout feature. It's a robust perennial that attracts a variety of pollinators. However, its toxicity to pets and potential for aggressive spread should be considered.

  • ✓ Attracts pollinators like bees and butterflies
  • ✓ Adds vibrant blue color to the garden
  • ✓ Relatively low-maintenance once established
  • ✓ Tolerates a range of soil types
  • ✓ Can be used in cut flower arrangements
  • ⚠️ Toxic to pets

📅 Maintenance Schedule — Plant Care Comparison

Black-Eyed Susan

Repotting Not typically needed as it's often grown as an annual. If grown as a perennial, repot every 2-3 years in spring.
Pruning Deadhead spent flowers regularly to encourage more blooms. Cut back foliage in late fall after it dies back.
Fertilizing Balanced liquid fertilizer (10-10-10) diluted to half strength, every 4-6 weeks during the growing season (spring and summer).
Seasonal Care Deadhead spent flowers to encourage continued blooming. In colder climates, treat as an annual or provide winter protection.

Bugloss

Repotting N/A (Outdoor plant)
Pruning Deadhead spent flowers to encourage further blooming. Cut back foliage in late fall after it has died back.
Fertilizing Apply a balanced fertilizer (10-10-10) in spring before new growth emerges. Avoid over-fertilizing, as this can lead to excessive foliage growth at the expense of flowers.
Seasonal Care Cut back spent flower stalks to encourage further blooming. In colder climates, mulch around the base of the plant to protect the roots during winter. Reduce watering in winter.

🌞 Light Requirements

Black-Eyed Susan

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

Low light tolerant: ❌ No

Bugloss

Full sun (at least 6 hours of direct sunlight per day)

Low light tolerant: ❌ No

💧 Watering Needs

Black-Eyed Susan

Water thoroughly when the top inch of soil feels dry to the touch. Avoid overwatering, which can lead to root rot. Allow excess water to drain away. Signs of underwatering include wilting leaves; overwatering includes yellowing leaves and soggy soil.

Bugloss

Water thoroughly when the top inch of soil feels dry. Avoid overwatering, which can lead to root rot. During hot, dry periods, more frequent watering may be necessary. Reduce watering in the fall and winter.

🌡️ Temperature & Humidity

Black-Eyed Susan

Temperature: 18-27°C

Humidity: 30-50%

Bugloss

Temperature: 15-25°C

Humidity: 30-50%

🤔 Which Plant Is Right For You?

Black-Eyed Susan

Black-Eyed Susan

Rudbeckia hirta
Care: Expert Time: 5-10 minutes weekly (deadheading) Beginner: No

Gardeners looking to add vibrant color and attract pollinators to their outdoor spaces.

✅ Choose This Plant If...

  • You want to attract pollinators to your garden.
  • You desire a long-blooming, cheerful flower.
  • You need a deer-resistant plant.
  • You want a low-maintenance outdoor plant once established.
  • You want a native North American wildflower.

❌ Skip This Plant If...

  • You have limited sunlight indoors.
  • You have pets that might ingest the plant.
  • You are looking for a low-maintenance INDOOR plant.
📍 Ideal Location: Outdoor garden, sunny border, meadow garden
🎨 Style: Cottage, Rustic, Wildflower
🏠 Apartment Friendly: No
⚠️ According to the ASPCA, Rudbeckia hirta contains glycosides that can be toxic to dogs, cats, and horses. Symptoms include dermatitis and gastrointestinal upset (vomiting, diarrhea). All parts of the plant are considered toxic.
Bugloss

Bugloss

Anchusa azurea
Care: Expert Time: 15 minutes weekly during the growing season. Beginner: No

Gardeners seeking a vibrant blue, pollinator-attracting perennial for sunny borders.

✅ Choose This Plant If...

  • You want a plant with vibrant blue flowers that attract pollinators.
  • You have a sunny garden border or cottage garden.
  • You are looking for a relatively low-maintenance perennial once established.
  • You want a plant that can tolerate a range of soil types.
  • You are aware of the toxicity to pets and can ensure it is planted where pets cannot access it.

❌ Skip This Plant If...

  • You have limited sunlight in your garden.
  • You have pets that may ingest the plant.
  • You prefer plants that are easy to control and don't spread aggressively.
📍 Ideal Location: Sunny garden border or cottage garden.
🎨 Style: Cottage, Bohemian, Traditional
🏠 Apartment Friendly: No
⚠️ Contains pyrrolizidine alkaloids, which are toxic to horses, dogs and cats. Symptoms include liver damage, photosensitization, and neurological signs. 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

☀️

Black-Eyed Susan needs full sun (at least 6-8 hours of direct sunlight daily), while Bugloss prefers full sun (at least 6 hours of direct sunlight per day).

📈

Black-Eyed Susan has moderate growth, while Bugloss grows fast.

💡 Pro Tips For Comparing These Plants

Black-Eyed Susan Care Tips

Black-Eyed Susans are primarily outdoor plants that require full sun and well-draining soil. Growing them indoors is extremely challenging due to their high light requirements. They are toxic to pets. Indoor survival is unlikely without specialized grow lights and careful monitoring.

  • Provide full sun for optimal blooming.
  • Ensure well-draining soil to prevent root rot.
  • Deadhead spent flowers regularly.
  • Water deeply but infrequently.
  • Monitor for pests and diseases.
❄️ Winter: In colder climates, cut back foliage after it dies back. Mulch around the base of the plant to provide winter protection. Consider treating as an annual in very cold regions.
☀️ Summer: Water regularly during dry spells. Deadhead spent flowers to encourage continued blooming. Monitor for pests and diseases.

Bugloss Care Tips

Anchusa azurea is an outdoor perennial that requires full sun and well-drained soil. It is not suitable for indoor growing due to its size and light requirements. It can spread aggressively via rhizomes. Toxicity to pets is a significant concern.

  • Provide full sun for optimal flowering.
  • Ensure well-drained soil to prevent root rot.
  • Deadhead spent flowers to encourage further blooming.
  • Monitor for pests and diseases, and treat promptly.
  • Be aware of the plant's toxicity to pets and take precautions.
❄️ Winter: Cut back dead foliage in late fall. Mulch around the base of the plant to protect the roots from freezing temperatures.
☀️ Summer: Water regularly during hot, dry periods. Deadhead spent flowers to encourage further blooming. Monitor for pests and diseases.

⚠️ Common Problems & Solutions — Plant Care Comparison

Black-Eyed Susan

Common Issues: Powdery mildew, fungal leaf spot, aphids, spider mites
Solutions: Powdery mildew/leaf spot: Improve air circulation, use a fungicide. Aphids/spider mites: Insecticidal soap or neem oil.

Bugloss

Common Issues: Powdery mildew, Slugs and snails, Root rot
Solutions: Ensure good air circulation to prevent powdery mildew. Use slug and snail bait or handpick pests. Improve soil drainage to prevent root rot.

❓ Frequently Asked Questions — Comparing These Plants

Black-Eyed Susan

What are the light requirements for Black-Eyed Susan?

Black-Eyed Susans are sun-loving plants and require at least 6 hours of direct sunlight each day to thrive. Insufficient light can lead to leggy growth, reduced blooming, and pale foliage. When grown indoors, place them near a south-facing window where they can receive ample sunlight. If natural light is limited, supplement with grow lights to ensure they get the light they need.

How do I care for Black-Eyed Susan?

Black-Eyed Susans thrive in full sun, requiring at least 6 hours of direct sunlight daily. Well-draining soil is crucial to prevent root rot; amend heavy clay soils with compost or sand. Water regularly, especially during dry periods, but avoid overwatering. Fertilize sparingly with a balanced fertilizer in the spring to encourage blooming. Deadhead spent flowers to promote continuous blooming throughout the season.

How do I propagate Black-Eyed Susan?

Black-Eyed Susans can be propagated through division or seeds.

Bugloss

What are the light requirements for Bugloss?

Bugloss flourishes in full sun, requiring at least six hours of direct sunlight daily. However, it can also tolerate partial shade, especially in hotter climates. Insufficient light can lead to leggy growth and reduced flowering. When grown indoors, place Bugloss near a sunny window, preferably south-facing. Rotate the plant regularly to ensure even light exposure. If natural light is limited, consider supplementing with grow lights to promote healthy growth and abundant blooms. Monitor the plant for signs of light stress, such as pale or yellowing leaves, and adjust its position accordingly. Remember, adequate light is crucial for the plant’s overall health and flowering potential.

How do I care for Bugloss?

Bugloss thrives in well-draining soil and requires moderate watering, allowing the soil to dry slightly between waterings. Provide full sun to partial shade for optimal growth and flowering. Fertilize sparingly with a balanced fertilizer during the growing season (spring and summer). Deadhead spent flowers to encourage continuous blooming. Bugloss is relatively low-maintenance, but regular monitoring for pests and diseases is recommended. Ensure good air circulation to prevent fungal issues. Prune back after flowering to maintain shape and promote bushier growth. Repotting is generally not required frequently, but if the plant becomes root-bound, move it to a slightly larger container. Bugloss is generally hardy and can tolerate a range of temperatures, but protection from extreme frost is advisable.

How do I propagate Bugloss?

Bugloss can be propagated through division, stem cuttings, and, in some cases, root cuttings. For division, carefully separate the plant at the roots in spring or fall. For stem cuttings, take 4-6 inch cuttings from new growth, remove lower leaves, and root in water or moist potting mix. Rooting hormone can improve success. For root cuttings, take 2-3 inch sections of root and plant horizontally in moist soil. Keep the soil consistently moist until new growth appears. Division is generally the easiest and most reliable method for Bugloss. Ensure the parent plant is healthy before attempting propagation. Provide adequate light and humidity to the new propagules.

Last updated: April 24, 2026 — Plant care data reviewed and verified by our editorial team.