Fact Sheets And Publications
Find out how YOU can get involved!
Hands-on experiential learning for UD undergrads!
Read our latest accomplishments!
Browse available resources.
Submit a sample today.
Analyses to help manage your land.
Chat with a DE Master Gardener.
You have questions. We have answers!
Contact UD Extension staff.
Protect your family, friends and community.
Onion
General information
- Scientific Name: Allium cepa
- Family: Alliaceae, Amaryllidaceae
- Cool season
- Planting Window: mid-March to mid-April
- pH = 5.5-7.0
- Planting Depth:
- Seeds: 1/2 inch, direct sow in soil
- Sets: lay in hole, roots down, cover with soil half way up the bulb
- MPD: 3 inches (in both directions)
- Can be companion planted with cabbage family members, beets, tomatoes and lettuce
- Tip: onions like rich, composted soil!
View factsheet as PDF
Pests and diseases
- Onion maggot - use floating row covers to prevent flies from infesting plants
Successful cultivars and harvest
- Cultivars:
- Seeds: White Lisbon Bunching (60 days)
- Sets: available sets Stuttgarter
- To harvest, pull from ground when tops are brown
- Harvest green onions mid-May through late June; harvest large onions late July through late August
- If storing onions, allow tops to wilt, cut off 1-2 inches above bulb and dry for one week
This publication was created by Master Gardener Rick Judd and designed by Extension Scholar Taylor Trent. Photos courtesy of Rick Judd.
UD Cooperative Extension
This institution is an equal opportunity provider.
In accordance with Federal law and U.S. Department of Agriculture policy, Cooperative Extension is prohibited from discriminating on the basis of race, color, national origin, sex, age, or disability.