When to Plant Stevia in Josephine County, OR
Josephine County, Oregon gardeners: here's your May plan
We've pulled the most time-sensitive tasks for Josephine County, Oregon this May and put them front and centre. Tackle them in order.
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Transplant stevia outside
Bring a watering can to the bed. Each transplant gets a drink the moment it's in the ground, not ten minutes later.
Before June arrives, get these ready
- Starting indoors: 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.
Josephine County, Oregon is in USDA Zone 8b. The average last spring frost is April 22 and the first fall frost is October 20, giving you a growing season of approximately 181 days.
At an elevation of 340 feet, Josephine County receives approximately 52.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 90°F, providing good warmth for Stevia during the growing season. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Stevia root diseases.
Josephine County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.2
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 Josephine County
How your county's soil matches Stevia's growing requirements.
Soil pH
Your soil pH (5.7–6.2) is more acidic than Stevia prefers (6.5–7.5). Add garden lime to raise pH.
Soil Texture
The silt loam soil in Josephine County is excellent for Stevia — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (4.4%) — Stevia will thrive.
How to Plant Stevia
Succession Planting Stevia
Sow every 6.9 weeks. Last sowing by Jul 22 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 | — | 8.4" | 0" | ❄️ Dormant |
| Feb | — | 6.6" | 0" | ❄️ Dormant |
| Mar | — | 6.2" | 0" | ❄️ Dormant |
| Apr | 2.2" | 3.6" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 2" | 0.2" | 💧 Light watering |
| Jul | 2.2" | 0.8" | 1.4" | 🚿 Regular watering |
| Aug | 2.2" | 0.9" | 1.3" | 🚿 Regular watering |
| Sep | 2.2" | 1.9" | 0.3" | 💧 Light watering |
| Oct | 2.2" | 4.4" | 0" | ✅ Rainfall sufficient |
| Nov | — | 7.4" | 0" | ❄️ Dormant |
| Dec | — | 8.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Josephine 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 — Josephine County, OR
Stevia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 4 | Mar 4 – Mar 18 |
| Transplant Outdoors | May 6 | May 6 – May 20 |
| Direct Sow | April 29 | Apr 29 – May 20 |
| Harvest | July 8 | Jul 8 – Sep 16 |
Plant 0.5" deep · 8" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Direct Sow |
| May | Transplant Outdoors Direct Sow |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Harvest |
| 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_acidic
🗺️ USDA Zone
Zone 8b
📆 Growing Season
181 days in Josephine County
Growing Tips for Stevia in Josephine County
Direct sow Stevia outdoors after April 22 in Josephine County when soil has warmed and frost danger has passed.
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 Josephine County, OR?
Josephine County is in Zone 8b with an average last frost of April 22. Plan your Stevia planting based on this frost date — see the calendar above for exact timing.
What planting zone is Josephine County, OR?
Josephine County, Oregon is in USDA Hardiness Zone 8b. The average last spring frost is April 22 and first fall frost is October 20.
Your Josephine County Garden Planner — Free
A 24-page printable planner built for Josephine County (Zone 8b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.