Onion
Allium cepa
Also called Onions and Shallot
Garden plant · Herbs, veg & fruitStop watering once the tops flop — that's it ripening, and wet bulbs rot in storage.
Care at a glance
- Ease
- Medium
- Water
- Every 5 daysWater the ground — water at the base, in the morning, not over the leaves.
- Light
- Full sun
- Feed
- Every 30 days
- Humidity
- Low
- Hardiness
- Hardy — an average winter RHS H4, to -10°C
- Size
- 0.3 m tall · 0.3 m across
- Lifecycle
- Biennial
- Origin
- Central Asia
Is it safe for pets and people?
PetsToxic to pets
Affects dogs, cats, horses. Signs: vomiting, damage to the red blood cells (anaemia), blood in the urine, weakness, a racing heart and panting.
PeopleNothing recorded against it
Safe to eat: the bulb.
Checked against ASPCA, RHS, Johnny's Selected Seeds and Clemson HGIC on 2026-07-31.
A guide, not veterinary or medical advice. If a pet or a person has eaten a plant and you are worried, call your vet or doctor now — don’t wait for signs to appear. Spotted a mistake? Tell us.
First signs of trouble
- Scattered plants in the row yellow and wilt from the leaf tips; ease one up and the base carries a dense white fluff dotted with black specks the size of poppy seeds.Onion white rot · disease
- Pale oval patches on the older leaves that go furry grey-violet on a damp morning, then fold over from the tip.Onion downy mildew · disease
- A hard round bulge starts up the middle of a leaf and stiffens into a flower stem — that bulb will not store, so use it first.Bolting · disorder