Onion vs Radish

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

Onion

Allium cepa

Amaryllidaceae · vegetables

EdibleDeer ResistantLow Maintenance

Radish

Raphanus sativus

Brassicaceae · vegetables

EdibleLow Maintenance

Hardiness Zone Range

Onion (Zones 3-9)

Radish (Zones 2-11)

Overlap: Both grow in zones 3–9

Detailed Comparison

Feature	Onion	Radish
Scientific Name	Allium cepa	Raphanus sativus
Family	Amaryllidaceae	Brassicaceae
Category	vegetables	vegetables
Sun	☀️ Full Sun	☀️ Full Sun
Water	💧💧 Medium	💧💧 Medium
Soil	Rich, Well-drained	Loose, Well-drained
Height	1' 6"	6"
Spread	4"	3"
Bloom Season	Summer	Spring, Fall
Bloom Color	White	White, Pink
Growth Rate	Medium	Fast
Native Region	Central Asia	Southeast Asia
Maintenance	Low	Low

Special Traits

Onion

Yes — EdibleYes — Deer ResistantNo — Drought Tolerant

Radish

Yes — EdibleNo — Deer ResistantNo — Drought Tolerant

Care Tips

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.

Radish

✓Direct sow — don't transplant.
✓Thin to 2 inches apart.
✓Harvest promptly to prevent pithy texture.
✓Great marker crop planted with slow-germinating carrots.

Which Plant Is Right for Your Garden?

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.

Choose Radish if you want a low-maintenance plant. It thrives in full sun with medium water in zones 2–11.

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

View OnionProfile →View RadishProfile →

Frequently Asked Questions

Can Onion and Radish grow in the same hardiness zone?

Onion grows in USDA zones 3-9, while Radish grows in zones 2-11. Both plants can grow together in zones 3 through 9.

Do Onion and Radish have the same sun and water needs?

Onion needs full sun and medium water, while Radish needs full sun and medium water. They share similar growing requirements and can be planted in the same bed.

Which grows taller, Onion or Radish?

Onion grows taller at 1' 6" compared to Radish at 6". Onion spreads 4" while Radish spreads 3".

Are Onion and Radish deer resistant?

Onion is deer resistant, but Radish is not. If deer are a concern, Onion is the better choice, or protect Radish with fencing.

Which is easier to maintain, Onion or Radish?

Both Onion and Radish 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	Onion	Radish
Scientific Name	Allium cepa	Raphanus sativus
Family	Amaryllidaceae	Brassicaceae
Category	vegetables	vegetables
Sun	☀️ Full Sun	☀️ Full Sun
Water	💧💧 Medium	💧💧 Medium
Soil	Rich, Well-drained	Loose, Well-drained
Height	1' 6"	6"
Spread	4"	3"
Bloom Season	Summer	Spring, Fall
Bloom Color	White	White, Pink
Growth Rate	Medium	Fast
Native Region	Central Asia	Southeast Asia
Maintenance	Low	Low

Care Tips

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.

Radish

✓Direct sow — don't transplant.
✓Thin to 2 inches apart.
✓Harvest promptly to prevent pithy texture.
✓Great marker crop planted with slow-germinating carrots.

Which Plant Is Right for Your Garden?

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.

Choose Radish if you want a low-maintenance plant. It thrives in full sun with medium water in zones 2–11.

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 Onion and Radish grow in the same hardiness zone?

Onion grows in USDA zones 3-9, while Radish grows in zones 2-11. Both plants can grow together in zones 3 through 9.

Do Onion and Radish have the same sun and water needs?

Onion needs full sun and medium water, while Radish needs full sun and medium water. They share similar growing requirements and can be planted in the same bed.

Which grows taller, Onion or Radish?

Onion grows taller at 1' 6" compared to Radish at 6". Onion spreads 4" while Radish spreads 3".

Are Onion and Radish deer resistant?

Onion is deer resistant, but Radish is not. If deer are a concern, Onion is the better choice, or protect Radish with fencing.

Which is easier to maintain, Onion or Radish?

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