When to plant Borage in Delta County, MI
Spring Borage in Delta County goes in April 28–May 19, once nighttime temps stop dipping near freezing. A second sowing from August 5 to August 19 extends the harvest into fall.
When to Plant Borage in Delta County, MI
June to-do list for Delta County, Michigan
Welcome to June in Zone 5a. These are the moves that will have the biggest impact on your growing season.
-
Get borage seeds going inside
You're about 16 weeks out from your last frost — the perfect window to get these germinating indoors.
-
Basket week: borage
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
July will be here before you know it — start on
- 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.
Delta County, Michigan is in USDA Zone 5a. The average last spring frost is May 12 and the first fall frost is October 14, giving you a growing season of approximately 155 days.
At an elevation of 921 feet, Delta County receives approximately 41.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Borage to ensure they mature before fall.
Delta County Soil Profile
Soil Type
Silt Loam
Soil pH
6.2-6.8
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 Delta County
How your county's soil matches Borage's growing requirements.
Soil pH
Your soil pH (6.2–6.8) is within Borage's preferred range (6.0–7.0).
Soil Texture
The silt loam soil in Delta County is excellent for Borage — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.8%) — Borage will thrive.
How to Plant Borage
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Borage
Sow every 5.7 weeks. Last sowing by Aug 15 to harvest before frost.
For a dedicated fall crop, sow by Aug 05.
Borage Water Budget
Water stress score is 6/10 — 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 | — | 1.8" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | — | 2.8" | 0" | ❄️ Dormant |
| Apr | — | 3.6" | 0" | ❄️ Dormant |
| May | 2.2" | 5.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 4.8" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.3" | 0" | ✅ Rainfall sufficient |
| Nov | — | 3.2" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Delta 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 — Delta County, MI
Borage Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | April 7 | Apr 7 – Apr 21 |
| Transplant Outdoors | May 5 | May 5 – May 19 |
| Direct Sow | April 28 | Apr 28 – May 19 |
| Harvest | June 30 | Jun 30 – Aug 18 |
| Fall Sowing | August 5 | Aug 5 – Aug 19 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | Start Indoors Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | Harvest |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | — |
| 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: ideal
🗺️ USDA Zone
Zone 5a
📆 Growing Season
155 days in Delta County
Growing Tips for Borage in Delta County
Direct sow Borage outdoors after May 12 in Delta 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 Delta County, MI?
Delta County is in Zone 5a with an average last frost of May 12. Plan your Borage planting based on this frost date — see the calendar above for exact timing.
What planting zone is Delta County, MI?
Delta County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 12 and first fall frost is October 14.
When should I plant Borage in Delta County, MI?
In Delta County, MI, plant Borage after the last frost (around May 12) and before the first frost (around October 14). Best results when soil holds above 50°F.
What growing zone is Delta County, MI for Borage?
Delta County sits in USDA Zone 5a. Borage grows reliably in zones 3a through 11b, so it's a good fit here.
Can Borage grow in Delta County's climate?
Yes — Borage grows well in Delta County's temperate climate. Delta County averages a 155-day frost-free season, with last frost around May 12 and first frost around October 14.
Your Delta County Garden Planner — Free
A 22-page printable planner built for Delta 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.