Onion
Also called Bulb onion, Spring onion.
| Light | full sun |
|---|---|
| Water | Every 6 days in the growing season, every 16 in winter |
| Humidity | medium |
| Difficulty | moderate |
| Height | Up to 40 cm (16 in) tall |
| Pets | Cats toxic, dogs toxic |
Source: ASPCA Animal Poison Control, toxic and non-toxic plants, Chives and Onion entries.
Edible here means commonly eaten. Nothing on this site is medical or dietary advice.
Toxic to cats and dogs if chewed. Toxic to cats, dogs and horses. The principle is N-propyl disulfide, which breaks down red blood cells, and every plant in the onion family carries it. Cooked or raw makes no difference. Keep it where an animal that eats houseplants cannot reach it, and speak to a vet if one does. In South Africa telephone the Poison Information Helpline on 0861 555 777; in the US, the ASPCA Animal Poison Control Center on (888) 426-4435.
Onions from sets are easier than onions from seed and are what most gardeners use: small bulbs pushed into firm ground in early spring, harvested when the tops fall over in midsummer. They bulb in response to day length, which is why a variety that works in one latitude disappoints in another and why the seed packet’s region matters more than usual. Keep them weed free, because onions have thin upright leaves and lose badly to competition. Stop watering once the bulbs are swelling and let them ripen dry, then lift, dry the necks thoroughly and store somewhere airy. Every part of the onion family is toxic to cats and dogs, which is worth knowing if you grow them where an animal digs.
Ailments observed
| Yellow leaves at the bottom of the plant | The natural end of the season as the bulbs ripen, or waterlogged ground. If it is midsummer and the tops are falling over, that is ripening. If it is early and the soil is wet, improve the drainage. |
|---|---|
| White or yellow mould on the compost | Onion white rot or neck rot in wet ground. Do not grow onions in the same ground for several years, and dry the harvested bulbs thoroughly before storing. |
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