When to Plant Onions: Best Timing, Tips, and Related Gardening Insights
When you're planning a garden that actually feeds you, onions, a hardy, storage-friendly vegetable that thrives in cool-to-mild conditions and is a staple in UK kitchens. Also known as bulb onions, they're one of the easiest crops to grow if you get the timing right. Plant them too early, and frost kills them. Too late, and they won’t swell into proper bulbs. The sweet spot? When to plant onions depends on your region, but across most of the UK, late February to early April is ideal for sets (small bulbs), while seeds go in from March to mid-April. It’s not magic—it’s just matching the plant’s needs to the weather.
Onions need well-drained, loose soil that’s not too rich. If your ground is heavy or clumpy, you’ll need to fix that before planting—just like you would for soil preparation, the process of improving soil structure for better root growth and water flow. Think about adding compost or sand to break up clay, or using raised beds if drainage is a problem. They also need full sun and consistent moisture, especially in the first few weeks. Forget about just tossing them in dirt like you might with grass seed—onions demand a little more care. And while you’re at it, keep weeds down. Weeds steal water and nutrients fast, and that’s why weed control, the practice of preventing unwanted plants from stealing resources from crops matters so much here. Mulch helps, and so does a good border around your onion patch.
Timing isn’t just about the calendar—it’s about what’s happening in your garden right now. If you’ve been working on organic gardening, a method of growing food without synthetic chemicals, using natural soil builders and pest solutions, you’re already ahead. Onions love compost-rich soil, and they respond well to natural feeds like seaweed extract. You don’t need fancy tools—just a trowel, a ruler to space them 10cm apart, and patience. And if you’ve ever wondered why your onions went soft or didn’t store well, it’s likely because they were harvested too early or cured improperly. That’s why the posts below cover everything from planting schedules to soil fixes, weed tricks, and even how to grow other veggies that play well with onions, like carrots or leeks.
What you’ll find here aren’t just generic tips. These are real, tested insights from people who’ve grown onions in UK gardens—from the damp south to the colder north. You’ll learn what works when the weather turns, how to avoid common mistakes, and how to turn a small patch into a winter supply of onions that lasts. No fluff. Just what you need to plant, grow, and harvest with confidence.