Black-Eyed Susan vs Delphinium

Side-by-side plant comparison — which is right for your garden?

Black-Eyed Susan

Rudbeckia hirta

Asteraceae · flowers

Deer ResistantDrought TolerantLow Maintenance

Delphinium

Delphinium elatum

Ranunculaceae · flowers

Deer ResistantHigh Maintenance

Hardiness Zone Range

Black-Eyed Susan (Zones 3-9)

Delphinium (Zones 3-7)

Overlap: Both grow in zones 3–7

Detailed Comparison

Feature	Black-Eyed Susan	Delphinium
Scientific Name	Rudbeckia hirta	Delphinium elatum
Family	Asteraceae	Ranunculaceae
Category	flowers	flowers
Sun	☀️ Full Sun	☀️ Full Sun
Water	💧💧 Medium	💧💧 Medium
Soil	Well-drained	Rich, Well-drained
Height	3'	6'
Spread	1' 6"	2'
Bloom Season	Summer-Fall	Early Summer
Bloom Color	Yellow	Blue, Purple, White, Pink
Growth Rate	Fast	Fast
Native Region	Eastern North America	Europe, Asia
Maintenance	Low	High

Special Traits

Black-Eyed Susan

No — EdibleYes — Deer ResistantYes — Drought Tolerant

Delphinium

No — EdibleYes — Deer ResistantNo — Drought Tolerant

Care Tips

Black-Eyed Susan

✓Deadhead spent blooms to encourage reblooming.
✓Divide clumps every 3-4 years.
✓Tolerates poor soil and drought once established.

Delphinium

✓Stake tall varieties.
✓Cut back after first bloom for possible rebloom.
✓Needs cool summers — struggles in heat.
✓Slugs love young growth.
✓All parts are toxic.

Which Plant Is Right for Your Garden?

Choose Black-Eyed Susan if you want a low-maintenance plant, need drought tolerance, and want deer resistance. It thrives in full sun with medium water in zones 3–9.

Choose Delphinium if you don't mind high maintenance, and want deer resistance. It thrives in full sun with medium water in zones 3–7.

Plant them together? Both overlap in zones 3–7. They share similar sun requirements (full sun), making them potential garden companions.

View Black-Eyed SusanProfile →View DelphiniumProfile →

Frequently Asked Questions

Can Black-Eyed Susan and Delphinium grow in the same hardiness zone?

Black-Eyed Susan grows in USDA zones 3-9, while Delphinium grows in zones 3-7. Both plants can grow together in zones 3 through 7.

Do Black-Eyed Susan and Delphinium have the same sun and water needs?

Black-Eyed Susan needs full sun and medium water, while Delphinium needs full sun and medium water. They share similar growing requirements and can be planted in the same bed.

Which grows taller, Black-Eyed Susan or Delphinium?

Delphinium grows taller at 6' compared to Black-Eyed Susan at 3'. Delphinium spreads 2' while Black-Eyed Susan spreads 1' 6".

Are Black-Eyed Susan and Delphinium deer resistant?

Yes, both Black-Eyed Susan and Delphinium are considered deer resistant, making them excellent choices for gardens in areas with deer pressure.

Which is easier to maintain, Black-Eyed Susan or Delphinium?

Black-Eyed Susan has low maintenance while Delphinium has high maintenance. Black-Eyed Susan may be easier for beginning gardeners to manage.

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Detailed Comparison

Feature	Black-Eyed Susan	Delphinium
Scientific Name	Rudbeckia hirta	Delphinium elatum
Family	Asteraceae	Ranunculaceae
Category	flowers	flowers
Sun	☀️ Full Sun	☀️ Full Sun
Water	💧💧 Medium	💧💧 Medium
Soil	Well-drained	Rich, Well-drained
Height	3'	6'
Spread	1' 6"	2'
Bloom Season	Summer-Fall	Early Summer
Bloom Color	Yellow	Blue, Purple, White, Pink
Growth Rate	Fast	Fast
Native Region	Eastern North America	Europe, Asia
Maintenance	Low	High

Care Tips

Black-Eyed Susan

✓Deadhead spent blooms to encourage reblooming.
✓Divide clumps every 3-4 years.
✓Tolerates poor soil and drought once established.

Delphinium

✓Stake tall varieties.
✓Cut back after first bloom for possible rebloom.
✓Needs cool summers — struggles in heat.
✓Slugs love young growth.
✓All parts are toxic.

Which Plant Is Right for Your Garden?

Choose Black-Eyed Susan if you want a low-maintenance plant, need drought tolerance, and want deer resistance. It thrives in full sun with medium water in zones 3–9.

Choose Delphinium if you don't mind high maintenance, and want deer resistance. It thrives in full sun with medium water in zones 3–7.

Plant them together? Both overlap in zones 3–7. They share similar sun requirements (full sun), making them potential garden companions.

Frequently Asked Questions

Can Black-Eyed Susan and Delphinium grow in the same hardiness zone?

Black-Eyed Susan grows in USDA zones 3-9, while Delphinium grows in zones 3-7. Both plants can grow together in zones 3 through 7.

Do Black-Eyed Susan and Delphinium have the same sun and water needs?

Black-Eyed Susan needs full sun and medium water, while Delphinium needs full sun and medium water. They share similar growing requirements and can be planted in the same bed.

Which grows taller, Black-Eyed Susan or Delphinium?

Delphinium grows taller at 6' compared to Black-Eyed Susan at 3'. Delphinium spreads 2' while Black-Eyed Susan spreads 1' 6".

Are Black-Eyed Susan and Delphinium deer resistant?

Yes, both Black-Eyed Susan and Delphinium are considered deer resistant, making them excellent choices for gardens in areas with deer pressure.

Which is easier to maintain, Black-Eyed Susan or Delphinium?

Black-Eyed Susan has low maintenance while Delphinium has high maintenance. Black-Eyed Susan may be easier for beginning gardeners to manage.