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When to Plant Lupine in Rich County, UT

Rich County, Utah Zone 5a June

June to-do list for Rich County, Utah

Here's what deserves your attention in Rich County, Utah this month. Everything below is tailored to Zone 5a and timed around your local frost dates.

Avg. last frost May 31
Avg. first frost September 15
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 15 hrs
  1. Transplant lupine outside

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Scatter lupine into prepared beds

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

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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.

Rich County, Utah is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 15, giving you a growing season of approximately 107 days.

At an elevation of 5,803 feet, Rich County receives approximately 18 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Lupine to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Lupine successfully. Mulch heavily to conserve soil moisture.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Rich County, UT (Zone 5a) Short season
107 days
Last Spring Frost May 31
107 growing days
First Fall Frost September 15

Rich County Soil Profile

Soil Type

Loam

Soil pH

6.5-8.2

Drainage

Well Drained

Lupine Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 12 Transplant: May 28 🌸 Bloom: Jul 23 – Sep 3
Recommended (50%) ✗ May not fit
Start indoors: Mar 29 Transplant: Jun 14 🌸 Bloom: Aug 9 – Sep 20
Safe Start (90%) ✓ Fits season (7 days to spare)
Start indoors: Apr 20 Transplant: Jul 6 🌸 Bloom: Aug 31 – Oct 12

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 Rich County

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

Soil pH

Your soil pH (6.5–8.2) is more alkaline than Lupine prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Rich County is excellent for Lupine — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.1%). Annual compost additions will help Lupine.

How to Plant Lupine

0.3"
Planting Depth
18"
Between Plants
24"
Between Rows

Lupine Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 335 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

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 1.3" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 4.3" 1.9" 2.4" 🚿 Regular watering
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 1.7" 2.6" 🚿 Regular watering
Aug 4.3" 1.7" 2.6" 🚿 Regular watering
Sep 4.3" 1.4" 2.9" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.1" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Rich County). 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 needs ~941 GDD — county provides 1,150 GDD Good fit

Lupine Planting Timeline — Rich County, UT

Lupine Planting Calendar

Activity When Date Range
Start Indoors March 29 Mar 29 – Apr 12
Transplant Outdoors June 14 Jun 14 – Jun 28
Direct Sow June 14 Jun 14 – Jul 5
Bloom August 9 Aug 9 – Sep 20

Plant 0.3" deep · 18" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May
June Transplant Outdoors Direct Sow
July Direct Sow
August Bloom
September Bloom
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

75–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 5a

📆 Growing Season

107 days in Rich County

Growing Tips for Lupine in Rich County

Direct sow Lupine outdoors after May 31 in Rich County when soil has warmed and frost danger has passed.

Your 107.0-day growing season in Rich County is tight for Lupine (75.0-100.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Lupine in this region include bean beetles and aphids. Use row covers early in the season and inspect plants weekly.

Rich County receives only 18" of rain annually. Lupine needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 →

Frequently Asked Questions

When should I plant Lupine in Rich County, UT?

Rich County is in Zone 5a with an average last frost of May 31. Plan your Lupine planting based on this frost date — see the calendar above for exact timing.

What planting zone is Rich County, UT?

Rich County, Utah is in USDA Hardiness Zone 5a. The average last spring frost is May 31 and first fall frost is September 15.

🌱

Your Rich County Garden Planner — Free

A 22-page printable planner built for Rich County (Zone 5a). 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 Rich County, UT. 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.