When to plant Borage in Lewis and Clark County County,
Borage planted in Lewis and Clark County County between May 22 and June 12 matures in 60 days — well before the September 18 first frost. A second sowing from June 26 to July 10 extends the harvest into fall.
When to Plant Borage in Lewis and Clark County, MT
What to do in June
Each item below is timed to Lewis and Clark County, Montana's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Get borage in for a late-season harvest
Fall crops get sweeter with a light frost. Don't be afraid of cool nights.
July prep starts now
- Starting indoors: borage
- First harvests: borage
Borage is a self-seeding annual herb with star-shaped blue flowers that attract pollinators. Its leaves have a cucumber-like flavor and the flowers are edible.
Lewis and Clark County, Montana is in USDA Zone 4b. The average last spring frost is May 29 and the first fall frost is September 18, giving you a growing season of approximately 112 days.
At an elevation of 7,064 feet, Lewis and Clark County receives approximately 22.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Borage to ensure they mature before fall.
Lewis and Clark County Soil Profile
Soil Type
Loam
Soil pH
6.5-8.1
Drainage
Well Drained
Borage 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 Lewis and Clark County
How your county's soil matches Borage's growing requirements.
Soil pH
Your soil pH (6.5–8.1) is more alkaline than Borage prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Lewis and Clark County is excellent for Borage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Borage.
How to Plant Borage
Fall planting: Sow 12 weeks before your first frost date for a fall harvest.
Succession Planting Borage
Sow every 5.7 weeks. Last sowing by Jul 20 to harvest before frost.
For a dedicated fall crop, sow by Jun 26.
Borage Water Budget
Water stress score is 8/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Borage
Borage needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.
| Month | Borage Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.3" | 0" | ❄️ Dormant |
| Apr | — | 2.3" | 0" | ❄️ Dormant |
| May | 2.2" | 2.6" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 1.5" | 0.7" | 💧 Light watering |
| Jul | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Aug | 2.2" | 2.3" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 1.8" | 0.4" | 💧 Light watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 1.4" | 0" | ❄️ Dormant |
| Dec | — | 1.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Lewis and Clark County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Borage 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.
Borage Planting Timeline — Lewis and Clark County, MT
Borage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 17 | Apr 17 – May 1 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 22 | May 22 – Jun 12 |
| Harvest | July 17 | Jul 17 – Sep 4 |
| Fall Sowing | June 26 | Jun 26 – Jul 10 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors |
| May | Start Indoors Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow Fall Sowing |
| July | Fall Sowing Harvest |
| August | Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
50–60 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 4b
📆 Growing Season
112 days in Lewis and Clark County
Growing Tips for Borage in Lewis and Clark County
Direct sow Borage outdoors after May 29 in Lewis and Clark County when soil has warmed and frost danger has passed.
General growing tips
Direct sow in spring as borage does not transplant well. Allow some plants to go to seed for next year. Young leaves are best; older leaves become bristly.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Borage in Other Locations
Frequently Asked Questions
When should I plant Borage in Lewis and Clark County, MT?
Lewis and Clark County is in Zone 4b with an average last frost of May 29. Plan your Borage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Lewis and Clark County, MT?
Lewis and Clark County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is May 29 and first fall frost is September 18.
When should I plant Borage in Lewis and Clark County County, ?
In Lewis and Clark County County, , plant Borage after the last frost (around May 29) and before the first frost (around September 18). Best results when soil holds above 50°F.
What growing zone is Lewis and Clark County County, for Borage?
Lewis and Clark County County sits in USDA Zone 4b. Borage grows reliably in zones 3a through 11b, so it's a good fit here.
Can Borage grow in Lewis and Clark County County's climate?
Yes — Borage grows well in Lewis and Clark County County's temperate climate. Lewis and Clark County County averages a 112-day frost-free season, with last frost around May 29 and first frost around September 18.
Your Lewis and Clark County Garden Planner — Free
A 22-page printable planner built for Lewis and Clark County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.