When to Plant Microgreens in Grundy County, TN
What to do in May
May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Grundy County, Tennessee.
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Start microgreens under lights
A seed-starting mix and a sunny window (or a grow light) are all you need. Keep soil warm — around 70°F — for fast germination.
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Start harvesting microgreens
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Microgreens are young seedlings of vegetables and herbs harvested at the cotyledon or first true leaf stage. They pack concentrated flavors and nutrients in a tiny package.
Grundy County, Tennessee is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.
At an elevation of 1,205 feet, Grundy County receives approximately 47.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 92°F, providing good warmth for Microgreens during the growing season.
Grundy County Soil Profile
Soil Type
Silt Loam
Soil pH
5.5-6.7
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 Grundy County
How your county's soil matches Microgreens's growing requirements.
Soil pH
Your soil pH (5.5–6.7) overlaps with Microgreens's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Grundy County is excellent for Microgreens — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Microgreens.
How to Plant Microgreens
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Microgreens
Sow every 0.7 weeks. Last sowing by Oct 08 to harvest before frost.
For a dedicated fall crop, sow by Aug 20.
Plant Water Budget
Monthly Watering Guide for Microgreens
Microgreens needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Microgreens Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.2" | 0" | ❄️ Dormant |
| Feb | — | 3.7" | 0" | ❄️ Dormant |
| Mar | — | 5.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| May | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Jun | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 5.1" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Oct | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Nov | — | 3.6" | 0" | ❄️ Dormant |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Grundy County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Microgreens 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.
Microgreens Planting Timeline — Grundy County, TN
Microgreens Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 2 | Mar 2 – Mar 16 |
| Transplant Outdoors | April 6 | Apr 6 – Apr 20 |
| Direct Sow | March 23 | Mar 23 – Apr 13 |
| Harvest | April 13 | Apr 13 – May 11 |
| Fall Sowing | August 20 | Aug 20 – Sep 3 |
Plant 0.5" deep · 2" apart · Rows 6" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
7–21 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
206 days in Grundy County
Growing Tips for Microgreens in Grundy County
Direct sow Microgreens outdoors after April 06 in Grundy County when soil has warmed and frost danger has passed.
Your generous 206.0-day season in Grundy County allows multiple plantings of Microgreens. Sow every 3.0 days for continuous harvest.
General growing tips
Sow seeds densely on shallow trays of moist growing medium. Cover until germination, then provide light. Harvest with scissors when 1-3 inches tall. Grow year-round indoors.
Microgreens in Other Locations
Frequently Asked Questions
When should I plant Microgreens in Grundy County, TN?
Grundy County is in Zone 7b with an average last frost of April 6. Plan your Microgreens planting based on this frost date — see the calendar above for exact timing.
What planting zone is Grundy County, TN?
Grundy County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is October 29.
Your Grundy County Garden Planner — Free
A 24-page printable planner built for Grundy 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.