When to Plant Larkspur in Clark County, NV
This month in Clark County, Nevada
We've pulled the most time-sensitive tasks for Clark County, Nevada this August and put them front and centre. Tackle them in order.
Looking ahead to September
- Fall sowing: larkspur
Larkspur (Consolida ajacis) is a cool-season annual that produces tall, delicate spires of blue, purple, pink, and white flowers reminiscent of its perennial cousin, delphinium. Direct-sown into cold soil or fall-sown in mild-winter climates, it blooms in spring before going to seed as summer heat arrives. An excellent cut flower and cottage-garden staple.
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 Larkspur may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Larkspur will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Larkspur successfully. Mulch heavily to conserve soil moisture.
Clark County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.3-8.4
Drainage
Well Drained
Larkspur Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Clark County
How your county's soil matches Larkspur's growing requirements.
Soil pH
Your soil pH (7.3–8.4) is more alkaline than Larkspur prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Clark County warms quickly in spring but drains fast. Larkspur will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Larkspur.
Organic Matter
Organic matter is low (0.8%). Add 2-3 inches of compost before planting Larkspur.
How to Plant Larkspur
Fall planting: Sow 9 weeks before your first frost date for a fall harvest.
Succession Planting Larkspur
Sow every 6.9 weeks. Last sowing by Aug 25 to harvest before frost.
For a dedicated fall crop, sow by Sep 21.
Larkspur Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Larkspur
Larkspur needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Larkspur Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 0.7" | 0" | ❄️ Dormant |
| Feb | 2.2" | 0.6" | 1.6" | 🚿 Regular watering |
| Mar | 2.2" | 0.6" | 1.6" | 🚿 Regular watering |
| Apr | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| May | 2.2" | 0.2" | 2" | 🚿 Regular watering |
| Jun | 2.2" | 0.3" | 1.9" | 🚿 Regular watering |
| Jul | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Aug | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Sep | 2.2" | 1.2" | 1" | 💧 Light watering |
| Oct | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Nov | 2.2" | 0.5" | 1.7" | 🚿 Regular watering |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Feb–Nov in Clark County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Larkspur Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Larkspur Planting Timeline — Clark County, NV
Larkspur Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | November 30 | Nov 30 – Mar 8 |
| Fall Sowing | September 21 | Sep 21 – Oct 5 |
Plant 0.1" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Bloom |
| February | Bloom |
| March | Bloom |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing |
| November | Bloom |
| December | Bloom |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · 1-2 times/week
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
268 days in Clark County
Growing Tips for Larkspur in Clark County
Direct sow Larkspur outdoors after February 28 in Clark County when soil has warmed and frost danger has passed.
Sandy soil in Clark County dries quickly — mulch Larkspur with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 111°F in Clark County, provide afternoon shade for Larkspur and water deeply in the morning.
Clark County receives only 9" of rain annually. Larkspur needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.
General growing tips
Larkspur does not transplant well — direct-sow only. In cold climates (zones 2–6), sow directly in early spring as soon as soil can be worked, 4–6 weeks before last frost; cold soil improves germination. In zones 7–10, fall-sow 8–10 weeks before first frost for spring bloom. Press seeds lightly into soil; they need darkness to germinate — cover with 1/8–1/4 inch of soil. Thin to 6–12 inches to prevent powdery mildew. Allow seed pods to mature and self-sow for naturalized colonies. All parts are toxic if ingested.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Larkspur in Other Locations
Frequently Asked Questions
When should I plant Larkspur in Clark County, NV?
Clark County is in Zone 9b with an average last frost of February 28. Plan your Larkspur 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.