Onions reward choosing the right variety early. Day length, planting stock and whether you want bulbs or greens shape the rest of the plan.
For full bulbs, start with a variety suited to your region’s day length and plant in sunny, well-drained soil. Keep weeds down and moisture consistent. Regrowing a kitchen onion for greens is a different project.
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Before you begin
Long-day, short-day and intermediate-day onions are not interchangeable. Use local extension guidance or a regional supplier before buying plants.
What you’ll need
- Region-appropriate onion sets or transplants
- Prepared bed or suitable container
- Small garden tool
- Water source
Optional tools & supplies
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Use what you already have. Choose supplies that fit your task, and check instructions and current prices.
Kings County Tools 17-in garden hoe and trowelLowe’s · ProductUse shallow strokes near plant roots and keep hands and feet clear of the edge.
NeverKink FLX 5/8-in x 50-ft garden hoseLowe’s · ProductChoose the length and fittings for your garden. Follow the hose’s drinking-water and temperature restrictions.
Back to the Roots organic potting mix, 1 cu ftLowe’s · ProductFor suitable plants in draining containers. Not orchid bark, and not an amendment to automatically add to every garden bed.
Let’s do this
Step by step
- 01
Choose the crop you want
Decide between full storage bulbs and green tops. For bulbs, select locally adapted sets or transplants. A grocery onion in a jar may grow leaves without producing a useful new storage crop.
- 02
Prepare an open, sunny bed
Loosen well-drained soil and remove weeds before planting. Use a soil test to guide amendments rather than guessing at fertilizer. In containers, use draining potting mix and adequate room for the variety.
- 03
Plant without burying the growing point
Set roots downward and follow your supplier’s depth and spacing. Leave room for mature bulbs; crowding for green onions is different from spacing a bulb crop.
- 04
Water and weed gently
Keep moisture reasonably even as plants establish. Onions compete poorly with weeds. Work shallowly around them so you do not damage roots or developing bulbs.
- 05
Match harvest to use
Pull green onions as needed. For storage onions, allow the crop to mature according to the variety and local guidance, then cure in a sheltered, airy place. Set damaged bulbs aside for prompt use.
Why a healthy onion might not make a big bulb
The variety may be responding to the wrong day length, or crowding, weeds and stress may limit growth. More fertilizer cannot fix the wrong regional type. Keep the variety name with your planting notes.
A quick final check
- Bulbs versus greens decided
- Day-length type matched
- Spacing allows growth
- Weeds controlled
Common questions & sticking points
Can I grow an onion from a kitchen scrap?
You can often regrow leaves, but that is not a reliable substitute for an adapted bulb variety.
Which type is right for Connecticut?
Long-day types are commonly used in northern areas; verify a specific variety with a local supplier or extension office.
Sources & further reading Optional
References used to check this guide. Follow your product’s own safety instructions where its design differs.
Last source check: September 24, 2026
