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When to Plant Lupine in Keith County, NE

Keith County, Nebraska Zone 5b July

What to do in July

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

Avg. last frost May 3
Avg. first frost October 7
Soil temp (4") 72°F
Watering High
Pest pressure High
Daylight 14.7 hrs
  1. Start lupine under lights

    Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.

  2. Bring in the lupine

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Get ahead of August
  • First harvests: lupine

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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.

Keith County, Nebraska is in USDA Zone 5b. The average last spring frost is May 3 and the first fall frost is October 7, giving you a growing season of approximately 157 days.

At an elevation of 1,091 feet, Keith County receives approximately 22 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Lupine to ensure they mature before fall.

Perennial Blooms in Spring Pollinator-friendly Deer-resistant Good for cutting
Keith County, NE (Zone 5b) Moderate season
157 days
Last Spring Frost May 3
157 growing days
First Fall Frost October 7

Keith County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.5

Drainage

Well Drained

Lupine Planting Risk Windows

Early Start (70% safe) ✓ Fits season (45 days to spare)
Start indoors: Feb 26 Transplant: May 14 🌸 Bloom: Jul 9 – Aug 20
Recommended (50%) ✓ Fits season (45 days to spare)
Start indoors: Mar 1 Transplant: May 17 🌸 Bloom: Jul 12 – Aug 23
Safe Start (90%) ✓ Fits season (45 days to spare)
Start indoors: Mar 11 Transplant: May 27 🌸 Bloom: Jul 22 – Sep 2

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 Keith County

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

Soil pH

Your soil pH (6.7–7.5) is more alkaline than Lupine prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) — Lupine will thrive.

How to Plant Lupine

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

Succession Planting Lupine

2
successive plantings in your 157-day season

Sow every 8.6 weeks. Last sowing by Jun 29 to harvest before frost.

Lupine Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 690 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.7" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.2" 0" ❄️ Dormant
May 4.3" 2.2" 2.1" 💧 Light watering
Jun 4.3" 1.7" 2.6" 🚿 Regular watering
Jul 4.3" 1.9" 2.4" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 4.3" 2.1" 2.2" 🚿 Regular watering
Oct 4.3" 1.7" 2.6" 🚿 Regular watering
Nov 1.5" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in Keith 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 ~1,072 GDD — county provides 1,923 GDD Excellent fit

Lupine Planting Timeline — Keith County, NE

Lupine Planting Calendar

Activity When Date Range
Start Indoors March 1 Mar 1 – Mar 15
Transplant Outdoors May 17 May 17 – May 31
Direct Sow May 17 May 17 – Jun 7
Bloom July 12 Jul 12 – Aug 23

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

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April
May Transplant Outdoors Direct Sow
June Direct Sow
July Bloom
August Bloom
September
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 5b

📆 Growing Season

157 days in Keith County

Growing Tips for Lupine in Keith County

Direct sow Lupine outdoors after May 03 in Keith County 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.

Keith County receives only 22" 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 Keith County, NE?

Keith County is in Zone 5b 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 Keith County, NE?

Keith County, Nebraska is in USDA Hardiness Zone 5b. The average last spring frost is May 3 and first fall frost is October 7.

🌱

Your Keith County Garden Planner — Free

A 22-page printable planner built for Keith County (Zone 5b). 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 Keith County, NE. Local conditions may vary. Last updated: July 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.