When to Plant Scallions in Decatur County, TN
What to do in May
May is a pivotal month for Decatur County, Tennessee gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Start scallions under lights
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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It's harvest week for scallions
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Looking ahead to June
- First harvests: scallions
Scallions (green onions) are mild-flavored alliums harvested for their slender green tops and white bases. They are quick-growing and perfect for succession planting.
Decatur County, Tennessee is in USDA Zone 7b. The average last spring frost is April 5 and the first fall frost is October 27, giving you a growing season of approximately 205 days.
At an elevation of 1,168 feet, Decatur County receives approximately 55 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Scallions during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Scallions root diseases.
Decatur County Soil Profile
Soil Type
Silt Loam
Soil pH
5.3-6.5
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 Decatur County
How your county's soil matches Scallions's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Scallions prefers (6.0–7.0). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Decatur County is excellent for Scallions — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.7%). Annual compost additions will help Scallions.
How to Plant Scallions
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Succession Planting Scallions
Sow every 5.7 weeks. Last sowing by Aug 18 to harvest before frost.
For a dedicated fall crop, sow by Aug 18.
Plant Water Budget
Monthly Watering Guide for Scallions
Scallions needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Scallions Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 4.2" | 0" | ❄️ Dormant |
| Feb | — | 4" | 0" | ❄️ Dormant |
| Mar | — | 4.6" | 0" | ❄️ Dormant |
| Apr | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| May | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 5.4" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 6.5" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 5.6" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 3.6" | 0.7" | 💧 Light watering |
| Oct | 4.3" | 3.1" | 1.2" | 💧 Light watering |
| Nov | — | 4" | 0" | ❄️ Dormant |
| Dec | — | 4.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Decatur County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Scallions 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.
Scallions Planting Timeline — Decatur County, TN
Scallions Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 1 | Mar 1 – Mar 15 |
| Transplant Outdoors | April 5 | Apr 5 – Apr 19 |
| Direct Sow | March 22 | Mar 22 – Apr 12 |
| Harvest | May 31 | May 31 – Jun 28 |
| Fall Sowing | August 18 | Aug 18 – Sep 1 |
Plant 0.5" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | Harvest |
| June | Harvest |
| July | — |
| August | Fall Sowing |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
50–70 days
🧪 Soil pH
Needs 6–7 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7b
📆 Growing Season
205 days in Decatur County
Growing Tips for Scallions in Decatur County
Direct sow Scallions outdoors after April 05 in Decatur County when soil has warmed and frost danger has passed.
Common pests for Scallions in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow every 3 weeks for continuous harvest. Thin to 1 inch apart or grow in clusters. Harvest when pencil-thick by pulling or cutting at soil level.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Scallions in Other Locations
Frequently Asked Questions
When should I plant Scallions in Decatur County, TN?
Decatur County is in Zone 7b with an average last frost of April 5. Plan your Scallions planting based on this frost date — see the calendar above for exact timing.
What planting zone is Decatur County, TN?
Decatur County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 5 and first fall frost is October 27.
Your Decatur County Garden Planner — Free
A 24-page printable planner built for Decatur 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.