When to Plant Zinnia in Clark County, NV
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.
Clark County, Nevada is in USDA Zone 9b. The average last spring frost is February 28 and the first fall frost is November 23, giving you a growing season of approximately 268 days.
At an elevation of 2,811 feet, Clark County receives approximately 9.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 111°F, so Zinnia may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Zinnia will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Zinnia successfully. Mulch heavily to conserve soil moisture.
Clark County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.0-7.0
Drainage
Well Drained
Zinnia Planting Timeline — Clark County, NV
Zinnia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 31 | Jan 31 – Feb 14 |
| Transplant Outdoors | January 31 | Jan 31 – Feb 14 |
| Direct Sow | January 31 | Jan 31 – Feb 21 |
| Bloom | April 11 | Apr 11 – Oct 10 |
Plant 0.3" deep · 12" apart · Rows 18" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Transplant Outdoors Direct Sow |
| February | Start Indoors Transplant Outdoors Direct Sow |
| March | — |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| 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 9b
📆 Growing Season
268 days in Clark County
Growing Tips for Clark 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 Clark County, NV?
Clark County is in Zone 9b with an average last frost of February 28. Plan your Zinnia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clark County, NV?
Clark County, Nevada is in USDA Hardiness Zone 9b. The average last spring frost is February 28 and first fall frost is November 23.
Your Clark County Garden Planner — Free
A 22-page printable planner built for Clark County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.