When to Plant Brussels Sprouts in Williamson County, TN
May in the garden — Williamson County, Tennessee
We've pulled the most time-sensitive tasks for Williamson County, Tennessee this May and put them front and centre. Tackle them in order.
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Indoor seed-starting week for brussels sprouts
You're about 24 weeks out from your last frost — the perfect window to get these germinating indoors.
Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.
Williamson County, Tennessee is in USDA Zone 7b. The average last spring frost is April 10 and the first fall frost is October 24, giving you a growing season of approximately 197 days.
At an elevation of 1,865 feet, Williamson County receives approximately 41.2 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Brussels Sprouts during the growing season.
Williamson 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 Williamson County
How your county's soil matches Brussels Sprouts's growing requirements.
Soil pH
Your soil pH (5.3–6.5) is more acidic than Brussels Sprouts prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Williamson County is excellent for Brussels Sprouts — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (3.0%). Annual compost additions will help Brussels Sprouts.
How to Plant Brussels Sprouts
Fall planting: Sow 10 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Brussels Sprouts
Brussels Sprouts needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.
| Month | Brussels Sprouts Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 3.6" | 0" | ❄️ Dormant |
| Mar | — | 3.8" | 0" | ❄️ Dormant |
| Apr | 3.9" | 2.8" | 1.1" | 💧 Light watering |
| May | 3.9" | 3.1" | 0.8" | 💧 Light watering |
| Jun | 3.9" | 3.9" | 0" | ✅ Rainfall sufficient |
| Jul | 3.9" | 3.8" | 0.1" | 💧 Light watering |
| Aug | 3.9" | 4.2" | 0" | ✅ Rainfall sufficient |
| Sep | 3.9" | 2.8" | 1.1" | 💧 Light watering |
| Oct | 3.9" | 2.9" | 1" | 💧 Light watering |
| Nov | — | 3.4" | 0" | ❄️ Dormant |
| Dec | — | 3.6" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Williamson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Brussels Sprouts 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.
Brussels Sprouts Planting Timeline — Williamson County, TN
Brussels Sprouts Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 6 | Mar 6 – Mar 20 |
| Transplant Outdoors | April 10 | Apr 10 – Apr 24 |
| Direct Sow | March 27 | Mar 27 – Apr 17 |
| Harvest | July 10 | Jul 10 – Sep 4 |
| Fall Sowing | August 15 | Aug 15 – Aug 29 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Fall Sowing Harvest |
| September | Harvest |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · Only during dry spells
📅 Days to Maturity
90–130 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 7b
📆 Growing Season
197 days in Williamson County
Growing Tips for Brussels Sprouts in Williamson County
Direct sow Brussels Sprouts outdoors after April 10 in Williamson County when soil has warmed and frost danger has passed.
Common pests for Brussels Sprouts in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Brussels Sprouts in Other Locations
Frequently Asked Questions
When should I plant Brussels Sprouts in Williamson County, TN?
Williamson County is in Zone 7b with an average last frost of April 10. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.
What planting zone is Williamson County, TN?
Williamson County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 10 and first fall frost is October 24.
Your Williamson County Garden Planner — Free
A 24-page printable planner built for Williamson 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.