When to Plant Celery by USDA Zone

Celery is a cool-season, long-maturing vegetable that requires careful timing for planting. Over my 30+ years of gardening, I’ve learned that planting celery at the right time for your USDA zone is critical for strong growth, tender stalks, and a bountiful harvest. Planting too early can stunt seedlings, while planting too late can result in stringy, bitter celery. This guide explains when to start celery seeds indoors and when to transplant outdoors based on USDA zones.

Table of Contents

General Planting Guidelines

Celery prefers cool weather with daytime temperatures of 60–70°F.
Long growing season: Celery takes 90–120 days from transplant to harvest.
Moisture needs: Keep soil consistently damp to prevent stringy stalks.

When to Plant Celery for a Spring Crop

For a spring crop, start celery seeds indoors 10–12 weeks before your last expected spring frost, as the plants need a long, cool growing season to mature. Transplant seedlings outdoors 2–3 weeks before the last frost date, once soil temperatures reach at least 50°F. Celery prefers steady, mild weather, so early planting ensures the plants can grow through cool spring days before the heat of summer arrives.

USDA Zone Spring Planting Schedule

USDA Zone	Indoor Seed Starting	Outdoor Transplanting	Notes
3–4	10–12 weeks before last frost	2–3 weeks after last frost	Protect seedlings with cloches or row covers
5–6	8–10 weeks before last frost	2 weeks after last frost	Ensure soil is well-prepared and rich
7–8	6–8 weeks before last frost	1–2 weeks before last frost	Can also direct sow in early spring
9–10	4–6 weeks before last frost	Late winter / early spring	Partial shade can prevent bolting in hot climates

Planting for a Fall Crop

When to Plant Celery for a Fall Crop

Celery is a cool-season vegetable that thrives in mild temperatures and needs a long growing season of 85–120 days. For a fall harvest, sow seeds indoors 10–12 weeks before your region’s first expected frost, then transplant seedlings outdoors once daytime highs stay below 75°F and nights are cool. In most areas, this means setting celery out in midsummer so it matures as temperatures drop. Consistent moisture and rich soil are key to tender, crisp stalks.

Fall Celery Planting Guide by USDA Zone

USDA Zone	Start Seeds Indoors	Transplant Outdoors	Expected Harvest
Zone 3	Early May	Late June	September–October
Zone 4	Mid–May	Early July	September–October
Zone 5	Late May	Mid–July	October
Zone 6	Early June	Late July	October–November
Zone 7	Mid–June	Early August	October–November
Zone 8	Late June	Mid–August	November–December
Zone 9	Early July	Late August	December–January
Zone 10	Mid–July	Early September	January–February

How to Use The Calendars:

Start seeds indoors based on your zone and frost dates.
Harden off seedlings for 1–2 weeks before transplanting.
Transplant outdoors according to the recommended timing to ensure strong, tender celery stalks.

Direct Sowing vs. Transplanting

Direct sowing: Best in milder zones with long growing seasons. Sow seeds ¼ inch deep in prepared soil.
Transplanting seedlings: Recommended for cooler zones to extend the growing season and protect young plants.

My Experience Tip

I’ve found that starting celery indoors even in warmer zones helps produce uniform, strong seedlings. Transplant them when they are 3–4 inches tall for best results.

Final Thoughts

Timing is crucial for celery. By following USDA zone-specific planting schedules, gardeners can ensure tender, crisp stalks and a productive harvest. Careful planning and moisture management make celery thriving possible in nearly any zone.