When to Plant Stevia in Washington County, TX
May to-do list for Washington County, Texas
Welcome to May in Zone 9a. These are the moves that will have the biggest impact on your growing season.
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Pick stevia
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
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.
Washington County, Texas is in USDA Zone 9a. The average last spring frost is March 2 and the first fall frost is November 27, giving you a growing season of approximately 270 days.
At an elevation of 386 feet, Washington County receives approximately 58.9 inches of rainfall annually with predominantly clay soil. Summer highs average 90°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.
Washington County Soil Profile
Soil Type
Clay
Soil pH
6.9-8.4
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 Washington County
How your county's soil matches Stevia's growing requirements.
Soil pH
Your soil pH (6.9–8.4) is more alkaline than Stevia prefers (6.5–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
Your clay soil in Washington County is workable for Stevia. Add compost annually to improve structure.
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 29 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 | — | 1.6" | 0" | ❄️ Dormant |
| Feb | — | 1.9" | 0" | ❄️ Dormant |
| Mar | 2.2" | 4.3" | 0" | ✅ Rainfall sufficient |
| Apr | 2.2" | 5.8" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 8.3" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 9.9" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 7.4" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 5.2" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 4.2" | 0" | ✅ Rainfall sufficient |
| Nov | 2.2" | 2" | 0.2" | 💧 Light watering |
| Dec | — | 1.4" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Washington 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 — Washington County, TX
Stevia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 19 | Jan 19 – Feb 2 |
| Transplant Outdoors | March 9 | Mar 9 – Mar 23 |
| Direct Sow | March 9 | Mar 9 – Mar 30 |
| Harvest | May 11 | May 11 – Jul 20 |
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 | — |
| 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: too_alkaline
🗺️ USDA Zone
Zone 9a
📆 Growing Season
270 days in Washington County
Growing Tips for Stevia in Washington County
Direct sow Stevia outdoors after March 02 in Washington County when soil has warmed and frost danger has passed.
With Washington County's clay soil (37% 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.
With 59" of annual rainfall in Washington County, ensure good drainage for Stevia — excess moisture can promote root rot and fungal diseases.
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 Washington County, TX?
Washington County is in Zone 9a with an average last frost of March 2. Plan your Stevia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Washington County, TX?
Washington County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is March 2 and first fall frost is November 27.
Your Washington County Garden Planner — Free
A 24-page printable planner built for Washington 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.