Onions

Most onion failures share one root cause: a day-length mismatch. Here’s how to diagnose bolting, thrips, and small bulbs — and fix them before next season.

Onions last 6 months or rot by September. The difference is a 2–3-week curing window, the right temps, and knowing your onion type.

Zone 9 gardeners who plant onions in spring almost always fail. Discover why fall is the only window that works, which short-day varieties thrive, and the exact planting calendar for zones 9a and 9b.

Start seeds in January, pick full-sized onions in August — zone 5 planting calendar, long-day variety picks, and the June deadline explained.

Zone 10 onion success comes down to timing and variety. Plant short-day types in fall, avoid spring planting, and follow this month-by-month guide for bulbs by spring.

Zone 7 onions thrive with fall planting and intermediate-day varieties. Get NC State-verified planting dates, the best cultivars, and Zone 7a vs 7b timing differences.

Zone 6 onion growers: the exact planting window by subzone, why sets over half an inch bolt, and the devernalization trick that saves a bad batch — sourced from university extension services.

Zone 4 gardeners: start onion seeds by late February, stop nitrogen when bulbs swell, and store Patterson or Copra for up to 12 months.

Learn exactly when to start onion seeds, which long-day varieties work in Zone 3, and how to harvest a full crop in an 80–110 day growing season.

Plant onions in October for Zone 8’s biggest bulbs — find the right short-day varieties for 8a/8b, exact planting dates, and humid-climate harvest tips.

Green onion vs chive: discover the key growing differences, flavor science, and which Allium herb belongs in your garden — or both.

Red and yellow onions are the same species but differ in anthocyanin pigment, pyruvic acid levels, storage life, and cure behavior. This guide compares day-length requirements, growing conditions, harvest timing, and best varieties for home gardens — with a quick comparison table and FAQ.

Onions are among the most useful companions in the vegetable garden. Their sulfur-based volatile compounds — the same chemistry that makes raw onions pungent and your eyes water when you slice them — interfere with the host-location ability of a range of pest insects, giving neighboring crops a measurable degree of protection. In return, certain plants benefit onions: attracting pest …

Walk the produce aisle or flip through a seed catalog and you’ll find a dozen onion types — each with a different shape, flavour profile, storage life, and cultural requirement. The mistake most gardeners make is choosing varieties by appearance alone, then wondering why their sweet onions turned sharp, or why their bulbs stayed golf-ball small. Day length — not …

Onions share the vegetable garden in silence — no sprawling vines, no towering canopy, no dramatic colour — but their impact on neighbouring plants runs deeper than most gardeners realise. Every part of an onion plant continuously releases volatile sulfur compounds into the surrounding soil and air: allicin, diallyl disulfide, and several related thiols that form the chemical signature behind …