Onion Plants for Sale: What Gardeners Need to Know

When searching for onion plants for sale, you'll find multiple options including onion sets, transplants, and seeds from garden centers, nurseries, and online retailers. The best time to purchase is early spring for most climates, with varieties like Yellow Sweet Spanish, Red Creole, and Walla Walla available. Quality plants should have firm bulbs, healthy roots, and no signs of disease or mold.

Looking for onion plants to grow your own fresh supply? You're in the right place. Whether you're a beginner gardener or expanding your vegetable patch, understanding what to look for when purchasing onion plants makes all the difference between a thriving crop and disappointing results. This guide cuts through the confusion to help you select the best onion plants for your garden.

Understanding Your Onion Plant Options

Before you buy, it's crucial to understand the three main forms of onion plants available for sale:

Type	Best For	Planting Time	Time to Harvest
Onion Sets	Beginners, short growing seasons	Early spring	80-100 days
Transplants	Reliable yields, specific varieties	Late winter to early spring	100-120 days
Seeds	Maximum variety selection, cost-effective	Indoors 8-10 weeks before last frost	120-150 days

According to the University of Minnesota Extension, sets offer the easiest growing experience but have fewer variety options, while seeds provide the widest selection but require more time and attention. Transplants strike a balance between convenience and variety selection.

Seasonal Availability and Timing

Timing your purchase correctly ensures your onion plants thrive. Onion plants for sale follow a predictable seasonal pattern:

• Late winter (February-March): First shipments of transplants arrive at garden centers in most regions
• Early spring (March-April): Peak availability of onion sets and transplants
• Late spring (May): Final opportunity to purchase for most climates

The USDA Plant Hardiness Zone Map determines your ideal planting window. In zones 3-5, purchase onion plants in late March to early April. Warmer zones (6-8) can buy from late February through March. Southern growers (zones 9-11) should look for short-day varieties available December through February.

What to Look for in Quality Onion Plants

Not all onion plants for sale deliver equal results. Examine plants carefully before purchasing:

Visual Inspection Checklist

• Bulb condition: Firm, dry outer skin without soft spots or mold
• Root development: White, healthy roots (avoid plants with brown, mushy roots)
• Shoot appearance: Green shoots should be crisp, not wilted or yellowed
• Packaging information: Clear labeling of variety, days to maturity, and growing requirements

Healthy onion transplants show no signs of disease or pest damage. The Oregon State University Extension Service warns that plants with premature flowering (bolting) indicators will produce smaller bulbs, so avoid any with flower stalks beginning to form.

Where to Find Reliable Onion Plants for Sale

While big box stores carry onion plants, specialty sources often provide better quality and variety:

Reputable Sources Compared

• Local nurseries: Best for regionally adapted varieties and expert advice
• University extension sales: Often sell disease-resistant varieties tested for your area
• Specialty seed companies: Wide variety selection with detailed growing information
• Farmers markets: Opportunity to buy from growers who can share firsthand experience

Avoid purchasing onion plants from sources that don't provide variety information or growing requirements. The USDA Agricultural Marketing Service notes that properly labeled plants indicate a seller who prioritizes plant quality and customer success.

Proper Handling After Purchase

How you handle onion plants immediately after purchase affects their performance:

• Store in a cool, dry place if not planting immediately (maximum 7 days)
• Keep roots moist but not wet during transport
• Never allow plants to freeze or overheat in your vehicle
• Plant within 2-3 days of purchase for best results

When planting, separate any clumped sets and ensure proper spacing (4-6 inches apart for bulb onions). The depth should be just enough to cover the roots with soil, leaving the top of the bulb slightly exposed.

Avoiding Common Purchasing Mistakes

Gardeners frequently make these errors when buying onion plants:

• Mistake: Buying the cheapest option without considering variety
  Solution: Match varieties to your climate (long-day for northern regions, short-day for southern)
• Mistake: Ignoring planting dates for your region
  Solution: Consult your local extension office for optimal timing
• Mistake: Purchasing plants with visible damage
  Solution: Inspect carefully and choose only healthy specimens

Remember that onion plants for sale in late spring often represent end-of-season clearance and may not perform as well as early-season purchases. The University of Wisconsin Extension reports that late-purchased plants have up to 30% lower yield potential due to heat stress.

Getting the Most from Your Onion Plants

After planting, proper care ensures a bountiful harvest:

• Water consistently (1 inch per week) but avoid overwatering
• Apply balanced fertilizer when plants reach 6 inches tall
• Monitor for thrips and other common onion pests
• Stop watering when bulbs begin to swell for best storage quality

Most onion varieties reach maturity 100-120 days after planting. Harvest when the tops naturally fall over and begin to yellow. Cure onions in a warm, dry location for 2-3 weeks before storing.

When is the best time to buy onion plants for sale?

The optimal time to purchase onion plants is early spring, typically March to April in most regions. Northern gardeners (zones 3-5) should buy in late March to early April, while southern growers (zones 9-11) should look for short-day varieties from December through February. Buying at the right time ensures plants are fresh and matched to your growing season.

What's the difference between onion sets and transplants?

Onion sets are small, immature bulbs that are easiest to plant but offer limited variety options. Transplants are young seedling plants that provide more variety choices and typically produce larger, more uniform bulbs. Sets work well for beginners with short growing seasons, while transplants give better results for gardeners seeking specific varieties or larger harvests.

How can I tell if onion plants are healthy before purchasing?

Examine onion plants for firm, dry bulbs without soft spots or mold. Roots should be white and healthy, not brown or mushy. Green shoots should appear crisp and vibrant, not wilted or yellowed. Avoid plants showing signs of premature flowering (bolting) as these will produce smaller bulbs. Properly labeled plants with variety information indicate a quality seller.

Can I grow onions from plants purchased at big box stores?

Yes, you can grow onions from big box store plants, but results may vary. These often carry limited varieties not specifically adapted to your region. For better results, purchase from local nurseries, specialty seed companies, or university extension sales that offer regionally appropriate varieties with proper growing information. Always inspect plants carefully for health before purchasing regardless of source.