When to Plant Lupine in Box Elder County, UT
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.
Box Elder County, Utah is in USDA Zone 6b. The average last spring frost is May 22 and the first fall frost is October 3, giving you a growing season of approximately 134 days.
At an elevation of 4,039 feet, Box Elder County receives approximately 24.5 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Lupine during the growing season.
Box Elder County Soil Profile
Soil Type
Loam
Soil pH
6.3-7.9
Drainage
Well Drained
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 | — | 1.5" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 1.9" | 0" | ❄️ Dormant |
| Apr | — | 2.7" | 0" | ❄️ Dormant |
| May | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Jun | 4.3" | 1.7" | 2.6" | 🚿 Regular watering |
| Jul | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Aug | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| Sep | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Oct | 4.3" | 2.4" | 1.9" | 💧 Light watering |
| Nov | — | 1.7" | 0" | ❄️ Dormant |
| Dec | — | 1.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Box Elder County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Lupine Planting Timeline — Box Elder County, UT
Lupine Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 29 | May 29 – Jun 12 |
| Direct Sow | May 29 | May 29 – Jun 19 |
| Bloom | July 24 | Jul 24 – Aug 28 |
Plant 0.3" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Moderate — regular watering
📅 Days to Maturity
75–100 days
🧪 Soil pH
Needs 5.5–7 · Your soil: N/A
🗺️ USDA Zone
Zone 6b
📆 Growing Season
134 days in Box Elder County
Growing Tips for Box Elder County
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 Box Elder County, UT?
Box Elder County is in Zone 6b with an average last frost of May 22. Plan your Lupine planting based on this frost date — see the calendar above for exact timing.
What planting zone is Box Elder County, UT?
Box Elder County, Utah is in USDA Hardiness Zone 6b. The average last spring frost is May 22 and first fall frost is October 3.
Your Box Elder County Garden Planner — Free
A 22-page printable planner built for Box Elder County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.