Butterfly Weed vs Onion

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

Butterfly Weed

Asclepias tuberosa

Apocynaceae · flowers

Deer ResistantDrought TolerantLow Maintenance

Onion

Allium cepa

Amaryllidaceae · vegetables

EdibleDeer ResistantLow Maintenance

Hardiness Zone Range

Butterfly Weed (Zones 3-9)

Onion (Zones 3-9)

Overlap: Both grow in zones 3–9

Detailed Comparison

Feature	Butterfly Weed	Onion
Scientific Name	Asclepias tuberosa	Allium cepa
Family	Apocynaceae	Amaryllidaceae
Category	flowers	vegetables
Sun	☀️ Full Sun	☀️ Full Sun
Water	💧 Low	💧💧 Medium
Soil	Well-drained, Sandy	Rich, Well-drained
Height	2' 6"	1' 6"
Spread	1' 6"	4"
Bloom Season	Summer	Summer
Bloom Color	Orange	White
Growth Rate	Medium	Medium
Native Region	Eastern North America	Central Asia
Maintenance	Low	Low

Special Traits

Butterfly Weed

No — EdibleYes — Deer ResistantYes — Drought Tolerant

Onion

Yes — EdibleYes — Deer ResistantNo — Drought Tolerant

Care Tips

Butterfly Weed

✓Deep taproot — don't transplant.
✓Direct sow or plant young.
✓Late to emerge in spring — mark location.
✓Monarch caterpillar host plant.

Onion

✓Match variety to your latitude — long-day for north, short-day for south.
✓Plant sets or transplants for easiest results.
✓Stop watering when tops fall over.
✓Cure for 2 weeks before storing.

Which Plant Is Right for Your Garden?

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

Choose Onion if you want a low-maintenance plant, and want deer resistance. It thrives in full sun with medium water in zones 3–9.

Plant them together? Both overlap in zones 3–9. They share similar sun requirements (full sun), making them potential garden companions.

View Butterfly WeedProfile →View OnionProfile →

Frequently Asked Questions

Can Butterfly Weed and Onion grow in the same hardiness zone?

Butterfly Weed grows in USDA zones 3-9, while Onion grows in zones 3-9. Both plants can grow together in zones 3 through 9.

Do Butterfly Weed and Onion have the same sun and water needs?

Butterfly Weed needs full sun and low water, while Onion needs full sun and medium water. Their differing requirements mean you may need separate garden areas for each.

Which grows taller, Butterfly Weed or Onion?

Butterfly Weed grows taller at 2' 6" compared to Onion at 1' 6". Butterfly Weed spreads 1' 6" while Onion spreads 4".

Are Butterfly Weed and Onion deer resistant?

Yes, both Butterfly Weed and Onion are considered deer resistant, making them excellent choices for gardens in areas with deer pressure.

Which is easier to maintain, Butterfly Weed or Onion?

Both Butterfly Weed and Onion have low maintenance requirements. They need a similar level of care including regular attention to watering, pruning, and soil health.

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Detailed Comparison

Feature	Butterfly Weed	Onion
Scientific Name	Asclepias tuberosa	Allium cepa
Family	Apocynaceae	Amaryllidaceae
Category	flowers	vegetables
Sun	☀️ Full Sun	☀️ Full Sun
Water	💧 Low	💧💧 Medium
Soil	Well-drained, Sandy	Rich, Well-drained
Height	2' 6"	1' 6"
Spread	1' 6"	4"
Bloom Season	Summer	Summer
Bloom Color	Orange	White
Growth Rate	Medium	Medium
Native Region	Eastern North America	Central Asia
Maintenance	Low	Low

Care Tips

Butterfly Weed

✓Deep taproot — don't transplant.
✓Direct sow or plant young.
✓Late to emerge in spring — mark location.
✓Monarch caterpillar host plant.

Onion

✓Match variety to your latitude — long-day for north, short-day for south.
✓Plant sets or transplants for easiest results.
✓Stop watering when tops fall over.
✓Cure for 2 weeks before storing.

Which Plant Is Right for Your Garden?

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

Choose Onion if you want a low-maintenance plant, and want deer resistance. It thrives in full sun with medium water in zones 3–9.

Plant them together? Both overlap in zones 3–9. They share similar sun requirements (full sun), making them potential garden companions.

Frequently Asked Questions

Can Butterfly Weed and Onion grow in the same hardiness zone?

Butterfly Weed grows in USDA zones 3-9, while Onion grows in zones 3-9. Both plants can grow together in zones 3 through 9.

Do Butterfly Weed and Onion have the same sun and water needs?

Butterfly Weed needs full sun and low water, while Onion needs full sun and medium water. Their differing requirements mean you may need separate garden areas for each.

Which grows taller, Butterfly Weed or Onion?

Butterfly Weed grows taller at 2' 6" compared to Onion at 1' 6". Butterfly Weed spreads 1' 6" while Onion spreads 4".

Are Butterfly Weed and Onion deer resistant?

Yes, both Butterfly Weed and Onion are considered deer resistant, making them excellent choices for gardens in areas with deer pressure.

Which is easier to maintain, Butterfly Weed or Onion?

Both Butterfly Weed and Onion have low maintenance requirements. They need a similar level of care including regular attention to watering, pruning, and soil health.