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When to Plant Lavender in Phillips County, CO

Lavender is a fragrant perennial herb with silvery foliage and purple flower spikes. It is prized for its essential oils, culinary uses, and ornamental beauty.

Phillips County, Colorado is in USDA Zone 5a. The average last spring frost is May 4 and the first fall frost is October 7, giving you a growing season of approximately 156 days.

At an elevation of 5,494 feet, Phillips County receives approximately 21.1 inches of rainfall annually with predominantly loam soil. Summer highs average 87ยฐF, providing good warmth for Lavender during the growing season.

Phillips County, CO (Zone 5a) Moderate season
156 days
Last Spring Frost May 4
156 growing days
First Fall Frost October 7

Phillips County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 7 🍅 Harvest: Aug 6 – Oct 22
Recommended (50%) ✗ May not fit
Transplant: May 11 🍅 Harvest: Aug 10 – Oct 26
Safe Start (90%) ✗ May not fit
Transplant: May 26 🍅 Harvest: Aug 25 – Nov 10

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 Phillips County

How your county's soil matches Lavender's growing requirements.

Soil pH

Your soil pH (6.5โ€“7.8) is within Lavender's preferred range (6.5โ€“8.0).

Soil Texture

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

Drainage

Drainage is adequate for Lavender.

Organic Matter

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

How to Plant Lavender

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

Plant Water Budget

Plant needs
0.3″/week
Rainfall provides
0.6″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Lavender

Lavender needs approximately 0.3 inches of water per week (1.3" per month). Here's how your county's rainfall compares month by month.

Month Lavender Needs Rainfall You Supplement Action
Jan โ€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 1.3" 0" โ„๏ธ Dormant
Mar โ€” 1.6" 0" โ„๏ธ Dormant
Apr โ€” 1.9" 0" โ„๏ธ Dormant
May 1.3" 2.8" 0" โœ… Rainfall sufficient
Jun 1.3" 1.5" 0" โœ… Rainfall sufficient
Jul 1.3" 1.6" 0" โœ… Rainfall sufficient
Aug 1.3" 2.5" 0" โœ… Rainfall sufficient
Sep 1.3" 1.7" 0" โœ… Rainfall sufficient
Oct 1.3" 1.8" 0" โœ… Rainfall sufficient
Nov โ€” 1.7" 0" โ„๏ธ Dormant
Dec โ€” 1.3" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Phillips County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Lavender 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.

Lavender needs ~2,211 GDD — county provides 2,379 GDD Good fit

Lavender Planting Timeline โ€” Phillips County, CO

Lavender Planting Calendar

Activity When Date Range
Transplant Outdoors May 11 May 11 โ€“ May 25
Harvest August 10 Aug 10 โ€“ Oct 26

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.3"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

90โ€“200 days

๐Ÿงช Soil pH

Needs 6.5โ€“8 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

156 days in Phillips County

Growing Tips for Lavender in Phillips County

Direct sow Lavender outdoors after May 04 in Phillips County when soil has warmed and frost danger has passed.

Your 156.0-day growing season in Phillips County is tight for Lavender (90.0-200.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant in well-drained, sandy soil. Avoid heavy mulching around the crown. Prune after flowering but do not cut into old wood. Lavender resents wet winter conditions.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Lavender in Phillips County, CO?

Phillips County is in Zone 5a with an average last frost of May 4. Plan your Lavender planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Phillips County, CO?

Phillips County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 4 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Phillips County gardeners in Zone 5a 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 Phillips County, CO. Local conditions may vary. Last updated: April 2026.