When to Plant Zinnia in Greene County, OH
Zinnia (Zinnia elegans) is a fast-growing, heat-loving annual that produces bold, dahlia-like blooms from early summer until hard frost. One of the easiest flowers to grow from direct-sown seed, zinnias thrive in hot, dry conditions and are magnets for butterflies and beneficial insects. They make excellent companion plants alongside marigolds in the vegetable garden.
Greene County, Ohio is in USDA Zone 6b. The average last spring frost is April 23 and the first fall frost is October 19, giving you a growing season of approximately 179 days.
At an elevation of 515 feet, Greene County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Zinnia during the growing season.
Greene County Soil Profile
Soil Type
Silt Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Zinnia Planting Timeline — Greene County, OH
Zinnia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 26 | Mar 26 – Apr 9 |
| Transplant Outdoors | April 23 | Apr 23 – May 7 |
| Direct Sow | April 23 | Apr 23 – May 14 |
| Bloom | July 2 | Jul 2 – Oct 8 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors Transplant Outdoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
60–70 days
🧪 Soil pH
Needs 5.5–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
179 days in Greene County
Growing Tips for Greene County
Direct-sow after last frost when soil reaches 60°F; seeds germinate in 5-7 days. In zones 3-5 a brief indoor start (4 weeks) is worthwhile but transplant carefully — zinnias dislike root disturbance. Deadhead frequently to extend bloom. Excellent cut flower; harvesting regularly encourages branching. Avoid overhead watering to reduce powdery mildew.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Zinnia in Other Locations
Frequently Asked Questions
When should I plant Zinnia in Greene County, OH?
Greene County is in Zone 6b with an average last frost of April 23. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Greene County, OH?
Greene County, Ohio is in USDA Hardiness Zone 6b. The average last spring frost is April 23 and first fall frost is October 19.
Your Greene County Garden Planner — Free
A 22-page printable planner built for Greene County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.