When to Plant Lupine in Haskell County, OK
Your August planting checklist for Haskell County, Oklahoma
We've pulled the most time-sensitive tasks for Haskell County, Oklahoma this August and put them front and centre. Tackle them in order.
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.
Haskell County, Oklahoma is in USDA Zone 7b. The average last spring frost is March 28 and the first fall frost is November 3, giving you a growing season of approximately 220 days.
At an elevation of 691 feet, Haskell County receives approximately 29.2 inches of rainfall annually with predominantly loam soil. Summer highs average 91°F, providing good warmth for Lupine during the growing season.
Haskell County Soil Profile
Soil Type
Loam
Soil pH
6.5-7.5
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 Haskell County
How your county's soil matches Lupine's growing requirements.
Soil pH
Your soil pH (6.5–7.5) overlaps with Lupine's range (5.5–7.0), though not a perfect match.
Soil Texture
The loam soil in Haskell County is excellent for Lupine — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Lupine will thrive.
How to Plant Lupine
Succession Planting Lupine
Sow every 8.6 weeks. Last sowing by Jul 26 to harvest before frost.
Lupine Water Budget
Water stress score is 6/10 — 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 | — | 0.7" | 0" | ❄️ Dormant |
| Feb | — | 1.1" | 0" | ❄️ Dormant |
| Mar | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Apr | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| May | 4.3" | 4" | 0.3" | 💧 Light watering |
| Jun | 4.3" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Aug | 4.3" | 3" | 1.3" | 💧 Light watering |
| Sep | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Oct | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Nov | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Dec | — | 0.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Haskell 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 Planting Timeline — Haskell County, OK
Lupine Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 31 | Jan 31 – Feb 14 |
| Transplant Outdoors | April 4 | Apr 4 – Apr 18 |
| Direct Sow | April 4 | Apr 4 – Apr 25 |
| Bloom | May 23 | May 23 – Jun 27 |
Plant 0.3" deep · 18" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors Direct Sow |
| May | Bloom |
| June | Bloom |
| July | — |
| August | — |
| 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: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
220 days in Haskell County
Growing Tips for Lupine in Haskell County
Direct sow Lupine outdoors after March 28 in Haskell 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.
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 Haskell County, OK?
Haskell County is in Zone 7b with an average last frost of March 28. Plan your Lupine planting based on this frost date — see the calendar above for exact timing.
What planting zone is Haskell County, OK?
Haskell County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is March 28 and first fall frost is November 3.
Your Haskell County Garden Planner — Free
A 22-page printable planner built for Haskell County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.