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When to plant Larkspur in Jefferson County, FL

Larkspur planted in Jefferson County between mid-spring and late spring matures in 60–90 days — well before the November 21 first frost. A second sowing from September 12 to September 26 extends the harvest into fall.

When to Plant Larkspur in Jefferson County, FL

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.

Jefferson County, Florida is in USDA Zone 9a. The average last spring frost is March 9 and the first fall frost is November 21, giving you a growing season of approximately 257 days.

At an elevation of 105 feet, Jefferson County receives approximately 56 inches of rainfall annually with predominantly sand soil. Summer highs average 95°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. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Larkspur root diseases.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Jefferson County, FL (Zone 9a) Long season
257 days
Last Spring Frost March 9
257 growing days
First Fall Frost November 21

Jefferson County Soil Profile

Soil Type

Sand

Soil pH

5.2-5.9

Drainage

Well Drained

Monthly Watering Guide for Larkspur

Larkspur needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Larkspur Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 2.9" 0" ❄️ Dormant
Mar 4.3" 3.2" 1.1" 💧 Light watering
Apr 4.3" 2.4" 1.9" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 7.8" 0" ✅ Rainfall sufficient
Jul 4.3" 8.9" 0" ✅ Rainfall sufficient
Aug 4.3" 7.4" 0" ✅ Rainfall sufficient
Sep 4.3" 6.4" 0" ✅ Rainfall sufficient
Oct 4.3" 5" 0" ✅ Rainfall sufficient
Nov 4.3" 2.5" 1.8" 💧 Light watering
Dec 2.7" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Jefferson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Larkspur Planting Timeline — Jefferson County, FL

Larkspur Planting Calendar

Activity When Date Range
Bloom November 21 Nov 21 – Mar 13
Fall Sowing September 12 Sep 12 – Sep 26

Plant 0.1" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January Bloom
February Bloom
March Bloom
April
May
June
July
August
September Fall Sowing
October
November Bloom
December Bloom

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Low — drought tolerant

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 9a

📆 Growing Season

257 days in Jefferson County

Growing Tips for Jefferson County

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 →

Frequently Asked Questions

When should I plant Larkspur in Jefferson County, FL?

Jefferson County is in Zone 9a with an average last frost of March 9. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jefferson County, FL?

Jefferson County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 9 and first fall frost is November 21.

When should I plant Larkspur in Jefferson County, FL?

In Jefferson County, FL, plant Larkspur after the last frost (around March 9) and before the first frost (around November 21). Best results when soil holds above 50°F.

What growing zone is Jefferson County, FL for Larkspur?

Jefferson County sits in USDA Zone 9a. Larkspur grows reliably in zones 2a through 10b, so it's a good fit here.

Can Larkspur grow in Jefferson County's climate?

Yes — Larkspur grows well in Jefferson County's temperate climate. Jefferson County averages a 257-day frost-free season, with last frost around March 9 and first frost around November 21.

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Your Jefferson County Garden Planner — Free

A 22-page printable planner built for Jefferson County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jefferson County, FL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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