Onion vs Parsley

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

Onion

Allium cepa

Amaryllidaceae · vegetables

EdibleDeer ResistantLow Maintenance

Parsley

Petroselinum crispum

Apiaceae · herbs

EdibleLow Maintenance

Hardiness Zone Range

Onion (Zones 3-9)

Parsley (Zones 5-9)

Overlap: Both grow in zones 5–9

Detailed Comparison

Feature	Onion	Parsley
Scientific Name	Allium cepa	Petroselinum crispum
Family	Amaryllidaceae	Apiaceae
Category	vegetables	herbs
Sun	☀️ Full Sun	☀️ Full Sun to Part Shade
Water	💧💧 Medium	💧💧 Medium
Soil	Rich, Well-drained	Rich, Moist
Height	1' 6"	1'
Spread	4"	1'
Bloom Season	Summer	Spring-Summer
Bloom Color	White	Yellow-green (second year)
Growth Rate	Medium	Medium
Native Region	Central Asia	Mediterranean
Maintenance	Low	Low

Special Traits

Onion

Yes — EdibleYes — Deer ResistantNo — Drought Tolerant

Parsley

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.

Parsley

✓Soak seeds overnight before planting — slow to germinate (3-4 weeks).
✓Harvest outer stems first.
✓Cut flower stalks to prolong leaf production.
✓Swallowtail butterfly host plant.

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 Parsley if you want a low-maintenance plant. It thrives in full sun to part shade with medium water in zones 5–9.

Plant them together? Both overlap in zones 5–9. However, they have different sun needs, so plan your garden layout carefully.

View OnionProfile →View ParsleyProfile →

Frequently Asked Questions

Can Onion and Parsley grow in the same hardiness zone?

Onion grows in USDA zones 3-9, while Parsley grows in zones 5-9. Both plants can grow together in zones 5 through 9.

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

Onion needs full sun and medium water, while Parsley needs full sun to part shade and medium water. Their differing requirements mean you may need separate garden areas for each.

Which grows taller, Onion or Parsley?

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

Are Onion and Parsley deer resistant?

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

Which is easier to maintain, Onion or Parsley?

Both Onion and Parsley 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	Parsley
Scientific Name	Allium cepa	Petroselinum crispum
Family	Amaryllidaceae	Apiaceae
Category	vegetables	herbs
Sun	☀️ Full Sun	☀️ Full Sun to Part Shade
Water	💧💧 Medium	💧💧 Medium
Soil	Rich, Well-drained	Rich, Moist
Height	1' 6"	1'
Spread	4"	1'
Bloom Season	Summer	Spring-Summer
Bloom Color	White	Yellow-green (second year)
Growth Rate	Medium	Medium
Native Region	Central Asia	Mediterranean
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.

Parsley

✓Soak seeds overnight before planting — slow to germinate (3-4 weeks).
✓Harvest outer stems first.
✓Cut flower stalks to prolong leaf production.
✓Swallowtail butterfly host plant.

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 Parsley if you want a low-maintenance plant. It thrives in full sun to part shade with medium water in zones 5–9.

Plant them together? Both overlap in zones 5–9. However, they have different sun needs, so plan your garden layout carefully.

Frequently Asked Questions

Can Onion and Parsley grow in the same hardiness zone?

Onion grows in USDA zones 3-9, while Parsley grows in zones 5-9. Both plants can grow together in zones 5 through 9.

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

Onion needs full sun and medium water, while Parsley needs full sun to part shade and medium water. Their differing requirements mean you may need separate garden areas for each.

Which grows taller, Onion or Parsley?

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

Are Onion and Parsley deer resistant?

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

Which is easier to maintain, Onion or Parsley?

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