When to Plant Radish in Alpena County, MI
Your May gardening checklist
Here's what deserves your attention in Alpena County, Michigan this month. Everything below is tailored to Zone 5a and timed around your local frost dates.
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Direct-sow radish
These tolerate cool soil, so you're not gambling by sowing now.
June prep starts now
- First harvests: radish
Radishes are one of the fastest-growing vegetables, with some varieties ready in under a month. They come in round, elongated, and large winter types.
Alpena County, Michigan is in USDA Zone 5a. The average last spring frost is May 19 and the first fall frost is October 3, giving you a growing season of approximately 137 days.
At an elevation of 984 feet, Alpena County receives approximately 31.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86°F, providing good warmth for Radish during the growing season.
Alpena County Soil Profile
Soil Type
Silt Loam
Soil pH
6-7.3
Drainage
Well Drained
Plant 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 Alpena County
How your county's soil matches Radish's growing requirements.
Soil pH
Your soil pH (6.0–7.3) overlaps with Radish's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Alpena County is excellent for Radish — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.3%) — Radish will thrive.
How to Plant Radish
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Radish
Sow every 2.4 weeks. Last sowing by Aug 29 to harvest before frost.
For a dedicated fall crop, sow by Jul 25.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Radish
Radish 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 | Radish Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.3" | 0" | ❄️ Dormant |
| Feb | — | 1.5" | 0" | ❄️ Dormant |
| Mar | — | 2.2" | 0" | ❄️ Dormant |
| Apr | — | 3.3" | 0" | ❄️ Dormant |
| May | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 3.5" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.2" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.3" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Oct in Alpena County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Radish 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.
Radish Planting Timeline — Alpena County, MI
Radish Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Direct Sow | May 5 | May 5 – May 26 |
| Harvest | June 2 | Jun 2 – Jun 23 |
| Fall Sowing | July 25 | Jul 25 – Aug 8 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | Direct Sow |
| June | Harvest |
| July | Fall Sowing |
| August | Fall Sowing |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
22–35 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
137 days in Alpena County
Growing Tips for Radish in Alpena County
Direct sow Radish outdoors after May 19 in Alpena County when soil has warmed and frost danger has passed.
Your generous 137.0-day season in Alpena County allows multiple plantings of Radish. Sow every 11.0 days for continuous harvest.
Common pests for Radish in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow every 1-2 weeks for continuous harvest. Do not transplant. Harvest spring radishes promptly to prevent them from becoming pithy and hot.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Radish in Other Locations
Frequently Asked Questions
When should I plant Radish in Alpena County, MI?
Alpena County is in Zone 5a with an average last frost of May 19. Plan your Radish planting based on this frost date — see the calendar above for exact timing.
What planting zone is Alpena County, MI?
Alpena County, Michigan is in USDA Hardiness Zone 5a. The average last spring frost is May 19 and first fall frost is October 3.
Your Alpena County Garden Planner — Free
A 24-page printable planner built for Alpena 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.