When to plant Larkspur in Juneau City and Borough County,
In Zone 7a (Juneau City and Borough County), direct-sow Larkspur between April 5 and April 26 for spring, after the May 3 last-frost mark. A second sowing from July 24 to August 7 extends the harvest into fall.
When to Plant Larkspur in Juneau City and Borough, AK
What to do in June
Your garden in Juneau City and Borough, Alaska is working on a schedule, even when you're not. Here's where you should be this June.
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Start harvesting larkspur
If you can't use it all right away, check the food-preservation section of your planner.
A few tasks this June that'll pay off in July
- First harvests: larkspur
- Fall sowing: 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.
Juneau City and Borough, Alaska is in USDA Zone 7a. The average last spring frost is May 3 and the first fall frost is October 2, giving you a growing season of approximately 152 days.
At an elevation of 930 feet, Juneau City and Borough receives approximately 35.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 57°F, so choose short-season varieties of Larkspur to ensure they mature before fall.
Juneau City and Borough Soil Profile
Soil Type
Silt Loam
Soil pH
5.1-6.5
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 Juneau City and Borough
How your county's soil matches Larkspur's growing requirements.
Soil pH
Your soil pH (5.1–6.5) is more acidic than Larkspur prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Juneau City and Borough is excellent for Larkspur — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (6.7%) — Larkspur will thrive.
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 Jul 04 to harvest before frost.
For a dedicated fall crop, sow by Jul 24.
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 | — | 2" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 1" | 0" | ❄️ Dormant |
| May | 2.2" | 1.6" | 0.6" | 💧 Light watering |
| Jun | 2.2" | 3.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 5.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 6.5" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.7" | 0" | ❄️ Dormant |
| Dec | — | 2.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Juneau City and Borough). 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 — Juneau City and Borough, AK
Larkspur Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | April 5 | Apr 5 – Apr 26 |
| Bloom | June 14 | Jun 14 – Aug 23 |
| Fall Sowing | July 24 | Jul 24 – Aug 7 |
Plant 0.1" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Direct Sow |
| May | — |
| June | Bloom |
| July | Fall Sowing Bloom |
| August | Fall Sowing Bloom |
| 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: too_acidic
🗺️ USDA Zone
Zone 7a
📆 Growing Season
152 days in Juneau City and Borough
Growing Tips for Larkspur in Juneau City and Borough
Direct sow Larkspur outdoors after May 03 in Juneau City and Borough 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 Juneau City and Borough, AK?
Juneau City and Borough is in Zone 7a with an average last frost of May 3. Plan your Larkspur planting based on this frost date — see the calendar above for exact timing.
What planting zone is Juneau City and Borough, AK?
Juneau City and Borough, Alaska is in USDA Hardiness Zone 7a. The average last spring frost is May 3 and first fall frost is October 2.
When should I plant Larkspur in Juneau City and Borough County, ?
In Juneau City and Borough County, , plant Larkspur after the last frost (around May 3) and before the first frost (around October 2). Best results when soil holds above 50°F.
What growing zone is Juneau City and Borough County, for Larkspur?
Juneau City and Borough County sits in USDA Zone 7a. Larkspur grows reliably in zones 2a through 10b, so it's a good fit here.
Can Larkspur grow in Juneau City and Borough County's climate?
Yes — Larkspur grows well in Juneau City and Borough County's temperate climate. Juneau City and Borough County averages a 152-day frost-free season, with last frost around May 3 and first frost around October 2.
Your Juneau City and Borough Garden Planner — Free
A 22-page printable planner built for Juneau City and Borough (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.