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When to plant Larkspur in Duval County County,

Aim to plant Larkspur in Duval County County on or after mid-spring; the window stays open through late spring. Duval County County's 279-day frost-free season gives you plenty of room for a spring and fall cycle. A second sowing from September 27 to October 11 extends the harvest into fall.

When to Plant Larkspur in Duval County, FL

Duval County, Florida Zone 9b June

Top priorities for Duval County, Florida gardeners in June

Your Duval County, Florida garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost February 24
Avg. first frost November 29
Soil temp (4") 88°F
Watering Low
Pest pressure High
Daylight 13.9 hrs

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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.

Duval County, Florida is in USDA Zone 9b. The average last spring frost is February 24 and the first fall frost is November 29, giving you a growing season of approximately 278 days.

At an elevation of 337 feet, Duval County receives approximately 56.9 inches of rainfall annually with predominantly sand soil. Summer highs average 102°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
Duval County, FL (Zone 9b) Year-round
278 days
Last Spring Frost February 24
278 growing days
First Fall Frost November 29

Duval County Soil Profile

Soil Type

Sand

Soil pH

5-5.8

Drainage

Well Drained

Larkspur Planting Risk Windows

Early Start (70% safe) ✓ Fits season (115 days to spare)
Transplant: Feb 11 🌸 Bloom: Apr 22 – Jul 29
Recommended (50%) ✓ Fits season (110 days to spare)
Transplant: Feb 24 🌸 Bloom: May 5 – Aug 11
Safe Start (90%) ✓ Fits season (106 days to spare)
Transplant: Mar 21 🌸 Bloom: May 30 – Sep 5

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 Duval County

How your county's soil matches Larkspur's growing requirements.

Soil pH

Your soil pH (5.0–5.8) is more acidic than Larkspur prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Duval County warms quickly in spring but drains fast. Larkspur will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (1.4%). Add 2-3 inches of compost before planting Larkspur.

How to Plant Larkspur

0.1"
Planting Depth
8"
Between Plants
12"
Between Rows

Fall planting: Sow 9 weeks before your first frost date for a fall harvest.

Succession Planting Larkspur

5
successive plantings in your 278-day season

Sow every 6.9 weeks. Last sowing by Aug 31 to harvest before frost.

For a dedicated fall crop, sow by Sep 27.

Larkspur Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

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 2.6" 0" ❄️ Dormant
Feb 2.2" 2.8" 0" ✅ Rainfall sufficient
Mar 2.2" 3.6" 0" ✅ Rainfall sufficient
Apr 2.2" 3" 0" ✅ Rainfall sufficient
May 2.2" 3.5" 0" ✅ Rainfall sufficient
Jun 2.2" 8.7" 0" ✅ Rainfall sufficient
Jul 2.2" 7.8" 0" ✅ Rainfall sufficient
Aug 2.2" 8.9" 0" ✅ Rainfall sufficient
Sep 2.2" 6.3" 0" ✅ Rainfall sufficient
Oct 2.2" 4.7" 0" ✅ Rainfall sufficient
Nov 2.2" 2.6" 0" ✅ Rainfall sufficient
Dec 2.4" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Duval 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 needs ~1,988 GDD — county provides 7,393 GDD Excellent fit

Larkspur Planting Timeline — Duval County, FL

Larkspur Planting Calendar

Activity When Date Range
Bloom December 6 Dec 6 – Mar 14
Fall Sowing September 27 Sep 27 – Oct 11

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 Fall Sowing
November
December Bloom

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: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

278 days in Duval County

Growing Tips for Larkspur in Duval County

Direct sow Larkspur outdoors after February 24 in Duval County when soil has warmed and frost danger has passed.

Sandy soil in Duval 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 102°F in Duval County, provide afternoon shade for Larkspur and water deeply in the morning.

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 →

Frequently Asked Questions

When should I plant Larkspur in Duval County, FL?

Duval County is in Zone 9b with an average last frost of February 24. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.

What planting zone is Duval County, FL?

Duval County, Florida is in USDA Hardiness Zone 9b. The average last spring frost is February 24 and first fall frost is November 29.

When should I plant Larkspur in Duval County, ?

In Duval County, , plant Larkspur after the last frost (around February 24) and before the first frost (around November 29). Best results when soil holds above 50°F.

What growing zone is Duval County, for Larkspur?

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

Can Larkspur grow in Duval County's climate?

Yes — Larkspur grows well in Duval County's temperate climate. Duval County averages a 279-day frost-free season, with last frost around February 24 and first frost around November 29.

🌱

Your Duval County Garden Planner — Free

A 22-page printable planner built for Duval 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.

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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 Duval County, FL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.