Ohio’s shorter growing season means starting collards indoors four weeks before the last frost. Finding the best time to plant collard greens in ohio is key to a healthy harvest before winter hits. Collards love cool weather, so timing matters more than you might think.
In Ohio, the last frost usually happens between late April and mid-May, depending on your zone. You want to get your plants in the ground when the soil is workable but not too cold. Let’s break down exactly when to start seeds indoors and when to transplant them outside.
Understanding Ohio’s Growing Zones For Collards
Ohio spans USDA hardiness zones 5b through 6b. Northern Ohio, near Lake Erie, is cooler and has a shorter growing season. Southern Ohio is warmer and can plant a bit earlier. Knowing your zone helps you nail the planting window.
Collards are frost-tolerant, so they can handle light freezes. But they grow best when temperatures are between 60°F and 75°F. If you plant too late, the heat will make them bitter and tough.
Zone 5B Planting Window
In northern Ohio, the last frost date is around May 10 to May 20. Start seeds indoors about 4 weeks before that, so mid-April. Transplant outdoors after the danger of hard frost passes.
Zone 6A And 6B Planting Window
Central and southern Ohio have last frost dates around April 20 to May 5. Start seeds indoors in late March or early April. You can transplant in late April or early May, depending on weather.
Best Time To Plant Collard Greens In Ohio
The ideal window for planting collard greens in Ohio is early spring for a summer harvest, and mid-summer for a fall harvest. Collards actually taste sweeter after a frost, so a fall crop is often better.
For spring planting, aim to transplant seedlings outdoors 2 to 4 weeks before the last frost date. For fall planting, sow seeds directly in the ground about 6 to 8 weeks before the first fall frost. In Ohio, the first frost usually hits between late September and mid-October.
Spring Planting Schedule
- Start seeds indoors: 4 weeks before last frost (mid-April for northern Ohio, late March for southern Ohio).
- Harden off seedlings: 1 week before transplanting. Place them outside for a few hours each day, increasing time.
- Transplant outdoors: 2 to 4 weeks before last frost date. Soil temperature should be at least 45°F.
- Protect from late frost: Use row covers or cloches if a hard freeze is forecast.
Fall Planting Schedule
- Direct sow seeds: 6 to 8 weeks before first fall frost (mid-July to mid-August in most of Ohio).
- Thin seedlings: Once they have 2-3 true leaves, space them 12-18 inches apart.
- Water regularly: Fall collards need consistent moisture, especially during dry August heat.
- Harvest after frost: The cold makes leaves sweeter. Pick leaves from the bottom up.
How To Start Collard Seeds Indoors In Ohio
Starting seeds indoors gives you a head start. Use seed-starting mix and small pots or trays. Plant seeds 1/4 inch deep and keep the soil moist but not soggy.
Place the trays in a warm spot, around 70°F. A sunny windowsill works, but grow lights are better for strong seedlings. Once they sprout, give them 12-16 hours of light per day.
Step-By-Step Indoor Seed Starting
- Fill pots with seed-starting mix. Moisten it before planting.
- Plant 2-3 seeds per pot. Later, thin to the strongest one.
- Cover with plastic wrap or a humidity dome to keep moisture in.
- Remove cover once seeds germinate, usually in 5-10 days.
- Water from the bottom to avoid damping off disease.
- Fertilize with a weak liquid fertilizer after 2 weeks.
Preparing Your Garden Soil For Collards
Collards need rich, well-draining soil with a pH between 6.0 and 7.5. Ohio soil can be clay-heavy, so amend it with compost or aged manure. Work the soil to at least 8 inches deep.
Add a balanced fertilizer like 10-10-10 before planting. Collards are heavy feeders, so they need plenty of nitrogen. Side-dress with compost or fertilizer mid-season for best growth.
Soil Preparation Checklist
- Test soil pH with a kit from a garden center.
- Add lime if pH is below 6.0. Add sulfur if above 7.5.
- Mix in 2-3 inches of compost or well-rotted manure.
- Remove rocks and weeds from the bed.
- Rake the soil smooth and water it a day before planting.
Transplanting Collard Seedlings Outdoors
Wait until seedlings have 4-6 true leaves before transplanting. Harden them off over a week by putting them outside in a sheltered spot. Start with 1 hour, then increase daily.
Space plants 12-18 inches apart in rows 18-24 inches apart. Dig holes slightly larger than the root ball. Place the seedling in, fill with soil, and water well. Mulch around plants to keep soil cool and moist.
Tips For Successful Transplanting
- Transplant on a cloudy day or in late afternoon to reduce shock.
- Water deeply after planting. Keep soil moist for the first week.
- Use row covers if temperatures drop below 25°F.
- Add a layer of straw or shredded leaves for mulch.
- Fertilize with a liquid starter fertilizer at transplant time.
Direct Sowing Collard Seeds In Ohio
Direct sowing is easier for fall crops. Plant seeds 1/4 to 1/2 inch deep in moist soil. Space seeds 2-3 inches apart, then thin to 12-18 inches once they grow.
For spring, direct sowing is risky because soil is cold and wet. Seeds may rot. It’s better to start indoors for spring. For fall, direct sowing works great because soil is warm and germination is fast.
Direct Sowing Steps For Fall
- Prepare the bed as described above.
- Sow seeds 1/2 inch deep, 2 inches apart.
- Cover lightly with soil and water gently.
- Keep soil moist until seeds germinate, about 5-10 days.
- Thin seedlings to 12-18 inches apart when they have 2-3 leaves.
- Mulch around plants to retain moisture and suppress weeds.
Caring For Collard Plants Through The Season
Collards need consistent watering, about 1-1.5 inches per week. Ohio summers can be dry, so check soil moisture regularly. Water at the base to prevent leaf diseases.
Fertilize every 3-4 weeks with a nitrogen-rich fertilizer. Fish emulsion or compost tea works well. Side-dress with compost halfway through the season for a boost.
Common Pests And Problems In Ohio
- Cabbage worms: Hand pick or use BT (Bacillus thuringiensis).
- Aphids: Spray with neem oil or insecticidal soap.
- Slugs and snails: Use diatomaceous earth or beer traps.
- Flea beetles: Use row covers early in the season.
- Club root: Rotate crops and avoid planting in the same spot each year.
Harvesting Collard Greens In Ohio
You can start harvesting outer leaves when the plant has 10-12 leaves. Pick from the bottom up, leaving the center to keep growing. Collards can be harvested into late fall, even after frost.
For the best flavor, wait until after a light frost. The cold converts starches to sugars, making leaves sweeter. In Ohio, this often happens in October or November.
Harvesting Tips
- Use a sharp knife or scissors to cut leaves cleanly.
- Leave at least 4-5 inner leaves for continued growth.
- Harvest in the morning when leaves are crisp.
- Wash leaves thoroughly to remove soil and bugs.
- Store in a plastic bag in the fridge for up to 2 weeks.
Extending The Growing Season With Protection
Ohio winters can be harsh, but collards are cold-hardy. You can extend your harvest into December or even January with some protection. Use cold frames, row covers, or hoop houses.
Mulch heavily around the base of plants with straw or leaves. This insulates the roots. On very cold nights, cover plants with blankets or frost cloth. Remove covers during the day if temperatures rise above freezing.
Season Extension Methods
- Cold frame: Build or buy a simple box with a glass or plastic top.
- Row cover: Lightweight fabric that lets light and water through.
- Hoop house: PVC pipes bent over the bed, covered with plastic.
- Heavy mulch: 6-8 inches of straw around plants.
- Cloches: Plastic jugs with bottoms cut off, placed over individual plants.
Common Mistakes When Planting Collards In Ohio
Many gardeners plant too late in spring, then the heat stunts growth. Others plant too early in fall, before the heat subsides. Timing is everything.
Another mistake is not thinning seedlings. Crowded plants produce small, tough leaves. Always thin to the recommended spacing. Also, don’t skip soil testing. Ohio soil can be acidic, and collards need neutral pH.
Mistakes To Avoid
- Planting seeds directly in cold, wet soil in spring.
- Waiting too long to transplant seedlings.
- Overwatering, which causes root rot.
- Underwatering during dry spells.
- Ignoring pest problems until it’s too late.
- Not rotating crops year to year.
Best Collard Varieties For Ohio
Some collard varieties handle Ohio’s climate better than others. Choose varieties that are cold-tolerant and slow to bolt in heat. Here are top picks:
- ‘Georgia Southern’: Classic variety, heat and cold tolerant.
- ‘Vates’: Dwarf variety, good for small gardens, very cold hardy.
- ‘Champion’: Slow to bolt, tender leaves, great for fall.
- ‘Flash’: Fast-growing, good for spring planting.
- ‘Blue Max’: Large leaves, very cold tolerant, good for winter harvest.
Frequently Asked Questions
What Is The Best Month To Plant Collard Greens In Ohio?
For spring, plant seeds indoors in April and transplant in May. For fall, direct sow seeds in July or August. The exact month depends on your zone, but these are general guidelines.
Can I Plant Collard Greens In Ohio In August?
Yes, August is perfect for a fall crop. Direct sow seeds in early to mid-August for a harvest before the first hard frost. The cooler weather in fall improves flavor.
How Late Can I Plant Collard Greens In Ohio?
You can plant collards as late as early September in southern Ohio, but the harvest will be smaller. For a good fall crop, aim for mid-August at the latest. Plants need at least 6-8 weeks before frost.
Do Collard Greens Survive Winter In Ohio?
Collards can survive mild winters with protection. They tolerate temperatures down to about 20°F. With row covers or cold frames, you can harvest into December or even January in some areas.
Should I Start Collard Seeds Indoors Or Direct Sow In Ohio?
For spring, start seeds indoors to avoid cold soil. For fall, direct sow is easier and works well. Starting indoors gives you more control and a longer growing season.
Final Tips For Growing Collards In Ohio
Collards are one of the easiest greens to grow in Ohio. They are forgiving and productive. Just focus on timing, soil prep, and consistent care.
Remember to water deeply and regularly, especially during dry spells. Mulch helps keep soil cool and moist. Harvest leaves regularly to encourage new growth. And don’t be afraid to leave some plants in the ground after frost for the sweetest flavor.
With the right timing and a little effort, you can enjoy fresh collard greens from your Ohio garden from spring through late fall. Start your seeds indoors in early spring, transplant after the last frost, and plant a second crop in mid-summer for a fall harvest. That’s the best way to make the most of Ohio’s growing season.
Happy gardening! Your collards will thank you for the careful planning. And your dinner table will be full of nutritious, homegrown greens for months.