When to Plant Onions in Richmond: Complete Guide + Best Varieties for Zone 7b

Richmond gardeners have a distinct advantage when it comes to growing onions—our Zone 7b climate sits perfectly in the transition zone where both spring and fall planting succeed beautifully. After forty years of vegetable gardening in Virginia, I can tell you that timing is everything with onions, and getting it right means the difference between baseball-sized bulbs and disappointing buttons.

Best Onion Varieties for Richmond's Zone 7b Climate

Richmond sits at 37°N latitude, placing us perfectly in the transition zone where intermediate-day onions thrive. These varieties need 12-14 hours of daylight to trigger bulbing, which aligns perfectly with our Virginia growing season.

Understanding Day-Length Requirements

Here's what most gardeners don't realize: onions won't form bulbs until they receive their specific day-length trigger. Plant the wrong type for your latitude, and you'll get massive green tops but tiny bulbs—or worse, the plants will bolt and flower without bulbing at all.

Top Intermediate-Day Varieties for Richmond

The candy onion 🌿Allium cepa 'Candy' (KAN-dee) is my go-to recommendation for Richmond gardeners. It's bred specifically for our transitional latitude and produces reliable medium to large bulbs whether you plant in spring or fall. The flavor balances sweetness with enough bite for cooking, and it stores moderately well—about 4-5 months with proper curing.

For serious storage, nothing beats 🌿Allium cepa 'Red Wing' (RED-wing). This hybrid produces deep red bulbs that maintain their color through storage and keeps firm for 8-10 months when properly cured. The thick, papery skin protects against moisture loss and rot.

If you want bragging-rights onions, try 🌿Allium cepa 'Yellow Sweet Spanish' (yel-low sweet SPAN-ish). Given Richmond's long growing season, this variety can reach colossal size—I've grown them over a pound each. The flavor is mild enough to eat raw but develops complexity when cooked.

Specific Planting Dates for Richmond Virginia

Richmond's last frost averages April 14, but our onion planting schedule doesn't follow typical frost date calculations. Onions are remarkably cold-hardy and actually prefer cool weather for root establishment.

Spring Planting Schedule

February 15-March 15: Plant onion sets, transplants, or direct-seed for late summer harvest (August-September). This timing allows maximum leaf growth before the June solstice triggers bulbing. Soil temperature should be at least 35°F (2°C)—onions will grow slowly but steadily in cold soil.

March 15-April 1: Last chance for spring planting. Later plantings risk smaller bulbs because there's insufficient time for leaf development before day-length triggers bulbing.

Fall Planting Schedule (Overwintering)

October 1-November 15: Plant transplants for early summer harvest (May-June). This method works beautifully in Zone 7b because our winters are mild enough for survival yet cold enough to prevent premature bulbing.

The key to fall success is planting transplants, not sets. Sets often bolt when exposed to spring temperature fluctuations after winter dormancy. Transplants establish better root systems and show superior bolt resistance.

Garlic Planting in Richmond

Plant garlic cloves October 15-November 15 for June harvest. Garlic requires 4-6 weeks of cold exposure (vernalization) to form proper bulbs. Richmond's winter provides perfect conditions without the extreme cold that can damage cloves in northern zones.

Both hardneck varieties like 🌿Allium sativum 'Music' and softneck types like 🌿Allium sativum 'California Early' perform well here. Hardnecks produce scapes (flower stalks) in late spring that should be removed to maximize bulb size. Softnecks don't produce scapes and typically store longer.

Complete Growing Guide for Richmond Onions

Soil Preparation

Onions demand well-draining soil with high fertility. Richmond's clay-heavy soils need amendment with compost or aged manure to improve drainage and provide sustained nutrition. Work in 2-3 inches of compost before planting.

Test soil pH—onions prefer 6.0-6.8. Our Virginia soils often run slightly acidic (5.5-6.0), so you may need lime applied the previous fall to raise pH gradually.

Planting Techniques

Sets: Push into soil until only the tip shows, spacing 4 inches apart in rows 12 inches apart. Choose sets smaller than a dime—large sets tend to bolt.

Transplants: Trim roots to 2 inches and tops to 4 inches. Plant at the same depth they were growing, firming soil gently around roots.

Seeds: Start indoors 8-10 weeks before transplanting. Direct seeding works for fall planting but requires consistent moisture for germination.

Fertilization and Care

Onions are heavy nitrogen feeders during vegetative growth but require a complete fertilizer approach:

• Apply balanced fertilizer (10-10-10) at planting time

• Side-dress with nitrogen every 3-4 weeks until bulbing begins

• Stop all nitrogen feeding when you see the soil crack around bulb bases

• Maintain consistent moisture—1 inch per week including rainfall

• Mulch between rows to suppress weeds and retain moisture

The critical management point comes when bulbing begins, usually indicated by soil cracking around the plant base as bulbs expand. Cease nitrogen feeding immediately—continued nitrogen delays maturity and produces thick necks that won't cure properly.

Companion Planting

Onions complement most vegetables, particularly members of the brassica family. Plant alongside broccoli, cabbage, and kale for natural pest deterrence. The strong onion scent masks brassica odors that attract cabbage worms and flea beetles.

Avoid planting near legumes (beans and peas), as onions can inhibit their nitrogen fixation ability.

Troubleshooting Richmond-Specific Problems

Bolting Issues

Spring-planted sets sometimes bolt (send up flower stalks) during Richmond's variable spring weather. Cool periods followed by sudden warmth trick large sets into thinking they've experienced winter and need to reproduce.

Prevention: Use smaller sets (pea-sized), choose transplants over sets, or plant intermediate-day varieties that adapt better to temperature fluctuations.

Clay Soil Drainage

Richmond's clay soils retain moisture but can become waterlogged during our wet springs. Onions sitting in saturated soil develop root rot and fail to bulb properly.

Solutions: Build raised beds 6-8 inches high, incorporate coarse sand and compost to improve drainage, or plant in containers filled with well-draining potting mix.

Summer Heat Stress

Late-planted onions may struggle with Richmond's hot, humid summers. Symptoms include stunted growth, premature bulbing, and increased disease pressure.

Management: Ensure adequate mulching, maintain consistent moisture, provide afternoon shade during the hottest periods (July-August), and time plantings to avoid peak summer stress.

Disease Prevention

Richmond's humidity creates favorable conditions for onion diseases:

• Rotate onion family crops every 3-4 years to break disease cycles

• Ensure good air circulation by proper spacing

• Water at soil level to keep foliage dry

• Remove diseased plants immediately

• Choose disease-resistant varieties when available

Harvest and Storage in Virginia Climate

Harvest Timing

Harvest when 50-75% of tops have fallen over naturally—this indicates the plant has finished transferring nutrients from leaves to bulbs. Don't be tempted to bend tops over manually; this creates wounds and reduces storage life.

Spring-planted onions: Typically ready August-September
Fall-planted onions: Usually ready May-June
Garlic: Harvest when lower leaves turn brown but 5-6 green leaves remain, typically mid-June

Curing Process for Virginia Humidity

Richmond's summer humidity makes proper curing critical for storage success. After harvest:

• Brush off soil but don't wash

• Lay in single layer on screens or racks in shaded, well-ventilated area

• Maintain temperatures between 80-90°F (27-32°C) with good airflow

• Cure for 2-4 weeks until necks are tight and papery

• Move indoors if rain threatens during curing period

Our humid climate extends curing time compared to arid regions. Be patient—properly cured onions store significantly longer than rushed ones.

Long-Term Storage

Once cured, store onions in cool (32-40°F/0-4°C), dry conditions with good air circulation. Avoid temperature fluctuations that trigger sprouting.

Storage expectations in Richmond's climate:

• Storage varieties (Red Wing): 8-10 months

• Intermediate varieties (Candy): 4-5 months

• Sweet varieties (Walla Walla): 2-3 months

• Hardneck garlic: 6-8 months

• Softneck garlic: 10-12 months

Check stored onions monthly and remove any showing soft spots or sprouting to prevent spread to healthy bulbs.