When to plant Larkspur in Union County, FL
Union County gardeners should plant Larkspur between mid-spring and late spring in spring. With Union County's Zone 9a climate (last frost March 1), Larkspur needs 60–90 days to mature — plant by August 29 for a full harvest. A second sowing from September 18 to October 2 extends the harvest into fall.
When to Plant Larkspur in Union County, FL
June in Union County, Florida — your action list
Your garden in Union County, Florida is working on a schedule, even when you're not. Here's where you should be this June.
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.
Union County, Florida is in USDA Zone 9a. The average last spring frost is March 1 and the first fall frost is November 27, giving you a growing season of approximately 271 days.
At an elevation of 360 feet, Union County receives approximately 60.6 inches of rainfall annually with predominantly sand soil. Summer highs average 96°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.
Union County Soil Profile
Soil Type
Sand
Soil pH
5.2-6
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 Union County
How your county's soil matches Larkspur's growing requirements.
Soil pH
Your soil pH (5.2–6.0) is more acidic than Larkspur prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
Sandy soil in Union 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 (1.3%). Add 2-3 inches of compost before planting Larkspur.
How to Plant Larkspur
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Larkspur
Sow every 6.9 weeks. Last sowing by Aug 29 to harvest before frost.
For a dedicated fall crop, sow by Sep 18.
Larkspur Water Budget
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 | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 2.8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 8.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 10" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 7.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.5" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Union 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 — Union County, FL
Larkspur Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | November 27 | Nov 27 – Mar 19 |
| Fall Sowing | September 18 | Sep 18 – Oct 2 |
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 · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9a
📆 Growing Season
271 days in Union County
Growing Tips for Larkspur in Union County
Direct sow Larkspur outdoors after March 01 in Union County when soil has warmed and frost danger has passed.
Sandy soil in Union 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 96°F in Union 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 →
Larkspur in Other Locations
Frequently Asked Questions
When should I plant Larkspur in Union County, FL?
Union County is in Zone 9a with an average last frost of March 1. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union County, FL?
Union County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 1 and first fall frost is November 27.
When should I plant Larkspur in Union County, FL?
In Union County, FL, plant Larkspur after the last frost (around March 1) and before the first frost (around November 27). Best results when soil holds above 50°F.
What growing zone is Union County, FL for Larkspur?
Union 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 Union County's climate?
Yes — Larkspur grows well in Union County's temperate climate. Union County averages a 271-day frost-free season, with last frost around March 1 and first frost around November 27.
Your Union County Garden Planner — Free
A 22-page printable planner built for Union 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.