When to plant Larkspur in Scott County County,
Plant Larkspur in Scott County County from March 18 to April 8 in spring. Scott County County sits in USDA Zone 5b, with last frost around April 15 and first frost on October 17.
When to Plant Larkspur in Scott County, IA
Your June gardening checklist
We've pulled the most time-sensitive tasks for Scott County, Iowa this June and put them front and centre. Tackle them in order.
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Bring in the larkspur
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
A few tasks this June that'll pay off in July
- First harvests: 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.
Scott County, Iowa is in USDA Zone 5b. The average last spring frost is April 15 and the first fall frost is October 17, giving you a growing season of approximately 185 days.
At an elevation of 678 feet, Scott County receives approximately 37.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Larkspur to ensure they mature before fall.
Scott County Soil Profile
Soil Type
Silt Loam
Soil pH
5.8-6.7
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 Scott County
How your county's soil matches Larkspur's growing requirements.
Soil pH
Your soil pH (5.8–6.7) overlaps with Larkspur's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Scott County is excellent for Larkspur — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.6%) — Larkspur will thrive.
How to Plant Larkspur
Succession Planting Larkspur
Sow every 6.9 weeks. Last sowing by Jul 19 to harvest before frost.
Larkspur Water Budget
Water stress score is 6/10 — 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | — | 2.9" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Scott 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 — Scott County, IA
Larkspur Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 18 | Mar 18 – Apr 8 |
| Bloom | May 27 | May 27 – Jul 22 |
Plant 0.1" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5b
📆 Growing Season
185 days in Scott County
Growing Tips for Larkspur in Scott County
Direct sow Larkspur outdoors after April 15 in Scott County when soil has warmed and frost danger has passed.
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 Scott County, IA?
Scott County is in Zone 5b with an average last frost of April 15. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.
What planting zone is Scott County, IA?
Scott County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 15 and first fall frost is October 17.
When should I plant Larkspur in Scott County County, ?
In Scott County County, , plant Larkspur after the last frost (around April 15) and before the first frost (around October 17). Best results when soil holds above 50°F.
What growing zone is Scott County County, for Larkspur?
Scott County County sits in USDA Zone 5b. Larkspur grows reliably in zones 2a through 10b, so it's a good fit here.
Can Larkspur grow in Scott County County's climate?
Yes — Larkspur grows well in Scott County County's temperate climate. Scott County County averages a 185-day frost-free season, with last frost around April 15 and first frost around October 17.
Your Scott County Garden Planner — Free
A 22-page printable planner built for Scott County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.