Onion Sets: How to Plant, Grow, and Harvest for Big Bulbs

This step-by-step guide walks you through exactly how to plant onion sets, including soil prep, proper spacing, planting depth, and watering tips.

5 from 2 votes

Print Pin

Author: Hilda Sterner

Prepare the Bed: Loosen soil 6 inches deep. Work in compost and a balanced granular fertilizer.
Space the Sets: Plant sets 4-6 inches apart in rows 12 inches apart. Plant onion sets with the pointed end facing up, blunt side down.
Planting Depth: Push each set 1 inch into the soil, then cover with loose soil.
Water Gently: Water after planting. Keep soil moist but never waterlogged.

Don't skip the post; it's filled with great tips for a successful harvest!
Not all onions are created equal. Long-day onions do best in northern states, while short-day onions thrive in the south. If you pick the wrong type, you'll get lots of green tops… and sad, tiny bulbs.
Onions hate compacted soil. If the ground is hard, they'll stay small no matter how much you baby them. Mixing in compost or aged manure makes a huge difference.
Onions don't compete well with weeds. Even a little crowding can stunt their growth, so keep that bed clean.
A light layer of straw or shredded leaves helps retain moisture, keeps weeds down, and prevents soil from crusting over.
Don't plant onions in the same spot year after year. This helps prevent disease buildup and gives you healthier plants overall.

Did you try this recipe? Please leave a review and a star rating!