When to plant Larkspur in Marshall County, KS
The best window to plant Larkspur in Marshall County, is March 25–April 15, when soil warms to 50°F. Last frost typically hits April 22; first frost October 14.
When to Plant Larkspur in Marshall County, KS
Your July planting checklist for Marshall County, Kansas
Here's what deserves your attention in Marshall County, Kansas this month. Everything below is tailored to Zone 6a and timed around your local frost dates.
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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.
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.
Marshall County, Kansas is in USDA Zone 6a. The average last spring frost is April 22 and the first fall frost is October 14, giving you a growing season of approximately 175 days.
At an elevation of 840 feet, Marshall County receives approximately 22.7 inches of rainfall annually with predominantly loam soil. Summer highs average 84°F, so choose short-season varieties of Larkspur to ensure they mature before fall.
Marshall County Soil Profile
Soil Type
Loam
Soil pH
6.6-7.8
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 Marshall County
How your county's soil matches Larkspur's growing requirements.
Soil pH
Your soil pH (6.6–7.8) is more alkaline than Larkspur prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Marshall County is excellent for Larkspur — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Larkspur.
Organic Matter
Organic matter is excellent (4.0%) — Larkspur will thrive.
How to Plant Larkspur
Succession Planting Larkspur
Sow every 6.9 weeks. Last sowing by Jul 16 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 | — | 0.6" | 0" | ❄️ Dormant |
| Feb | — | 0.9" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.2" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 2.1" | 0.1" | 💧 Light watering |
| Oct | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Nov | — | 0.7" | 0" | ❄️ Dormant |
| Dec | — | 0.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Marshall 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 — Marshall County, KS
Larkspur Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | March 25 | Mar 25 – Apr 15 |
| Bloom | June 3 | Jun 3 – Jul 29 |
Plant 0.1" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Direct Sow |
| April | Direct Sow |
| May | — |
| June | Bloom |
| July | Bloom |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Only during dry spells
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 6a
📆 Growing Season
175 days in Marshall County
Growing Tips for Larkspur in Marshall County
Direct sow Larkspur outdoors after April 22 in Marshall County when soil has warmed and frost danger has passed.
Marshall County receives only 23" 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 Marshall County, KS?
Marshall County is in Zone 6a with an average last frost of April 22. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.
What planting zone is Marshall County, KS?
Marshall County, Kansas is in USDA Hardiness Zone 6a. The average last spring frost is April 22 and first fall frost is October 14.
When should I plant Larkspur in Marshall County, KS?
In Marshall County, KS, plant Larkspur after the last frost (around April 22) and before the first frost (around October 14). Best results when soil holds above 50°F.
What growing zone is Marshall County, KS for Larkspur?
Marshall County sits in USDA Zone 6a. Larkspur grows reliably in zones 2a through 10b, so it's a good fit here.
Can Larkspur grow in Marshall County's climate?
Yes — Larkspur grows well in Marshall County's temperate climate. Marshall County averages a 175-day frost-free season, with last frost around April 22 and first frost around October 14.
Your Marshall County Garden Planner — Free
A 22-page printable planner built for Marshall County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.