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When to Plant Stevia in Washington County, UT

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, Utah is in USDA Zone 8a. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 3,524 feet, Washington County receives approximately 12.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Stevia during the growing season. With low rainfall, drip irrigation is essential for growing Stevia successfully. Mulch heavily to conserve soil moisture.

Washington County, UT (Zone 8a) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Washington County Soil Profile

Soil Type

Loam

Soil pH

6.7-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (70 days to spare)
Start indoors: Jan 23 Transplant: Mar 27 🍅 Harvest: May 29 – Aug 7
Recommended (50%) ✓ Fits season (62 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jun 22 – Aug 31
Safe Start (90%) ✓ Fits season (31 days to spare)
Start indoors: Apr 8 Transplant: Jun 10 🍅 Harvest: Aug 12 – Oct 21

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 (6.7โ€“8.0) overlaps with Stevia's range (6.5โ€“7.5), though not a perfect match.

Soil Texture

The loam soil in Washington County is excellent for Stevia โ€” good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Stevia.

Organic Matter

Organic matter is moderate (2.4%). Annual compost additions will help Stevia.

How to Plant Stevia

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Stevia

4
successive plantings in your 209-day season

Sow every 6.9 weeks. Last sowing by Aug 03 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.3″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 881 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.6" 0" โ„๏ธ Dormant
Mar โ€” 1.1" 0" โ„๏ธ Dormant
Apr 2.2" 1.2" 1" ๐Ÿ’ง Light watering
May 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Jun 2.2" 0.9" 1.3" ๐Ÿšฟ Regular watering
Jul 2.2" 1.2" 1" ๐Ÿ’ง Light watering
Aug 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Sep 2.2" 0.9" 1.3" ๐Ÿšฟ Regular watering
Oct 2.2" 1.2" 1" ๐Ÿ’ง Light watering
Nov 2.2" 1" 1.2" ๐Ÿšฟ Regular watering
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Washington County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 needs ~1,312 GDD — county provides 3,657 GDD Excellent fit

Stevia Planting Timeline โ€” Washington County, UT

Stevia Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 โ€“ Mar 2
Transplant Outdoors April 20 Apr 20 โ€“ May 4
Direct Sow April 13 Apr 13 โ€“ May 4
Harvest June 22 Jun 22 โ€“ Aug 31

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September โ€”
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

209 days in Washington County

Growing Tips for Stevia in Washington County

Direct sow Stevia outdoors after April 06 in Washington 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 →

Frequently Asked Questions

When should I plant Stevia in Washington County, UT?

Washington County is in Zone 8a with an average last frost of April 6. Plan your Stevia planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Washington County, UT?

Washington County, Utah is in USDA Hardiness Zone 8a. The average last spring frost is April 6 and first fall frost is November 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Washington County gardeners in Zone 8a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Washington County, UT. Local conditions may vary. Last updated: April 2026.