When to plant Lupine in Juneau City and Borough County,
In Zone 7a (Juneau City and Borough County), direct-sow Lupine between May 10 and May 31 for spring, after the May 3 last-frost mark.
When to Plant Lupine in Juneau City and Borough, AK
Juneau City and Borough, Alaska gardeners: here's your June plan
June is a pivotal month for Juneau City and Borough, Alaska gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Get lupine seeds going inside
Give them 6–8 weeks indoors before the last frost and you'll transplant into warm soil with seedlings that are already leaping.
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Basket week: lupine
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
To set up a strong July, finish these tasks
- First harvests: lupine
Wild Lupine (Lupinus perennis) is a stunning native perennial of eastern North America, producing tall, densely packed spikes of pea-like flowers in deep blue-purple — the classic wildflower of sandy pine barrens and open woodlands. Russell Hybrid Lupins extend the color range to pink, red, yellow, and bicolors and produce larger flower spikes, making them popular cottage garden perennials. The palmately compound foliage is attractive throughout the season. Wild lupine is the sole larval host plant of the federally endangered Karner Blue butterfly, making it a high-value native planting. Seeds are toxic if ingested. Nitrogen-fixing roots improve surrounding soil over time.
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 Lupine 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
Lupine 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 Lupine's growing requirements.
Soil pH
Your soil pH (5.1–6.5) overlaps with Lupine's range (5.5–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Juneau City and Borough is excellent for Lupine — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (6.7%) — Lupine will thrive.
How to Plant Lupine
Succession Planting Lupine
Sow every 8.6 weeks. Last sowing by Jun 24 to harvest before frost.
Lupine Water Budget
Monthly Watering Guide for Lupine
Lupine needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Lupine Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 2" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 1.3" | 0" | ❄️ Dormant |
| Apr | — | 1" | 0" | ❄️ Dormant |
| May | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Jun | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Jul | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 6.5" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| 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.
Lupine 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.
Lupine Planting Timeline — Juneau City and Borough, AK
Lupine Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 8 | Mar 8 – Mar 22 |
| Transplant Outdoors | May 10 | May 10 – May 24 |
| Direct Sow | May 10 | May 10 – May 31 |
| Bloom | June 28 | Jun 28 – Aug 2 |
Plant 0.3" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | — |
| May | Transplant Outdoors Direct Sow |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
75–100 days
🧪 Soil pH
Needs 5.5–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7a
📆 Growing Season
152 days in Juneau City and Borough
Growing Tips for Lupine in Juneau City and Borough
Direct sow Lupine outdoors after May 03 in Juneau City and Borough when soil has warmed and frost danger has passed.
Common pests for Lupine in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Scarify seeds before planting — nick with a file or sandpaper, or soak in warm water for 24 hours — to improve germination. Start in biodegradable pots (peat or paper) 8–10 weeks before last frost to avoid disturbing the taproot at transplant. Direct sowing is equally effective if done fresh in fall (natural stratification and scarification over winter). Transplant or direct-sow after last frost into well-drained, lean soil. Lupines prefer cool, moist springs and decline in summer heat and humidity. They are relatively short-lived in warm zones (treat as biennial in Zones 7–8). Do not over-fertilize — nitrogen-fixers thrive in lean soil. Deadhead after bloom to extend season; allow some pods to mature for self-seeding. Year 2+ plants produce the largest flower spikes.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Lupine in Other Locations
Frequently Asked Questions
When should I plant Lupine in Juneau City and Borough, AK?
Juneau City and Borough is in Zone 7a with an average last frost of May 3. Plan your Lupine 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 Lupine in Juneau City and Borough County, ?
In Juneau City and Borough County, , plant Lupine 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 Lupine?
Juneau City and Borough County sits in USDA Zone 7a. Lupine grows reliably in zones 3a through 8b, so it's a good fit here.
Can Lupine grow in Juneau City and Borough County's climate?
Yes — Lupine 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.