When to Plant Stevia in Williamson County, TX
Your May game plan for Williamson County, Texas
Here's what deserves your attention in Williamson County, Texas this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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Harvest stevia as they ripen
This is the payoff month. Bring a basket, bring a friend, and get into the beds.
Looking ahead to June
- First harvests: stevia
Stevia is a subtropical herb whose leaves contain natural sweeteners 200-300 times sweeter than sugar. It is grown as an annual in most climates.
Williamson County, Texas is in USDA Zone 9a. The average last spring frost is March 5 and the first fall frost is November 22, giving you a growing season of approximately 262 days.
At an elevation of 1,023 feet, Williamson County receives approximately 53.3 inches of rainfall annually with predominantly clay soil. Summer highs average 94°F, providing good warmth for Stevia during the growing season. Clay soil retains moisture well for Stevia, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Stevia root diseases.
Williamson County Soil Profile
Soil Type
Clay
Soil pH
7.1-7.8
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 Stevia's growing requirements.
Soil pH
Your soil pH (7.1–7.8) overlaps with Stevia's range (6.5–7.5), though not a perfect match.
Soil Texture
Heavy clay soil (46% clay) in Williamson County compacts easily and drains slowly. Amend with compost and avoid working soil when wet.
Drainage
Drainage is adequate for Stevia.
Organic Matter
Organic matter is moderate (2.6%). Annual compost additions will help Stevia.
How to Plant Stevia
Succession Planting Stevia
Sow every 6.9 weeks. Last sowing by Aug 24 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Stevia
Stevia 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 | Stevia Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 2" | 0" | ❄️ Dormant |
| Mar | 2.2" | 3.4" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 6.5" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 7.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 7.6" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 6.6" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 6.1" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.4" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 1.7" | 0.5" | 💧 Light watering |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Williamson County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Stevia 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.
Stevia Planting Timeline — Williamson County, TX
Stevia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 22 | Jan 22 – Feb 5 |
| Transplant Outdoors | March 12 | Mar 12 – Mar 26 |
| Direct Sow | March 12 | Mar 12 – Apr 2 |
| Harvest | May 14 | May 14 – Jul 23 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | Transplant Outdoors Direct Sow |
| April | Direct Sow |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.5"/week · Natural rainfall sufficient
📅 Days to Maturity
60–90 days
🧪 Soil pH
Needs 6.5–7.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
262 days in Williamson County
Growing Tips for Stevia in Williamson County
Direct sow Stevia outdoors after March 05 in Williamson County when soil has warmed and frost danger has passed.
With Williamson County's clay soil (46% clay), work in 3-4 inches of compost before planting Stevia. Avoid tilling when soil is wet to prevent compaction.
Common pests for Stevia in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors under lights or buy transplants. Pinch flowers to encourage leaf production. Harvest leaves before flowering for maximum sweetness. Dry leaves for year-round use.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Stevia in Other Locations
Frequently Asked Questions
When should I plant Stevia in Williamson County, TX?
Williamson County is in Zone 9a with an average last frost of March 5. Plan your Stevia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Williamson County, TX?
Williamson County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 5 and first fall frost is November 22.
Your Williamson County Garden Planner — Free
A 24-page printable planner built for Williamson County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.