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When to Plant Dill in San Miguel County, CO

Dill is a feathery annual herb with aromatic leaves and seeds. Its fine foliage and umbrella-shaped flower heads attract beneficial insects to the garden.

San Miguel County, Colorado is in USDA Zone 5a. The average last spring frost is May 31 and the first fall frost is September 21, giving you a growing season of approximately 113 days.

At an elevation of 8,402 feet, San Miguel County receives approximately 21.6 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, providing good warmth for Dill during the growing season.

San Miguel County, CO (Zone 5a) Short season
113 days
Last Spring Frost May 31
113 growing days
First Fall Frost September 21

San Miguel County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (22 days to spare)
Start indoors: Apr 8 Transplant: May 6 🍅 Harvest: Jun 17 – Aug 19
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Apr 26 Transplant: May 24 🍅 Harvest: Jul 5 – Sep 6
Safe Start (90%) ✓ Fits season (11 days to spare)
Start indoors: May 23 Transplant: Jun 20 🍅 Harvest: Aug 1 – Oct 3

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 San Miguel County

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

Soil pH

Your soil pH (6.8โ€“7.6) is more alkaline than Dill prefers (5.5โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Dill.

How to Plant Dill

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

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Dill

3
successive plantings in your 113-day season

Sow every 4.6 weeks. Last sowing by Jul 23 to harvest before frost.

For a dedicated fall crop, sow by Jul 13.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/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 Dill

Dill 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 Dill Needs Rainfall You Supplement Action
Jan โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 1.4" 0" โ„๏ธ Dormant
Mar โ€” 2.1" 0" โ„๏ธ Dormant
Apr โ€” 2.4" 0" โ„๏ธ Dormant
May 2.2" 2.6" 0" โœ… Rainfall sufficient
Jun 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Jul 2.2" 1.7" 0.5" ๐Ÿ’ง Light watering
Aug 2.2" 2.5" 0" โœ… Rainfall sufficient
Sep 2.2" 1.5" 0.7" ๐Ÿ’ง Light watering
Oct โ€” 1.7" 0" โ„๏ธ Dormant
Nov โ€” 1.3" 0" โ„๏ธ Dormant
Dec โ€” 1.3" 0" โ„๏ธ Dormant

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

Dill 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.

Dill needs ~688 GDD — county provides 1,553 GDD Excellent fit

Dill Planting Timeline โ€” San Miguel County, CO

Dill Planting Calendar

Activity When Date Range
Start Indoors April 26 Apr 26 โ€“ May 10
Transplant Outdoors May 24 May 24 โ€“ Jun 7
Direct Sow May 17 May 17 โ€“ Jun 7
Harvest July 5 Jul 5 โ€“ Sep 6
Fall Sowing July 13 Jul 13 โ€“ Jul 27

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

40โ€“60 days

๐Ÿงช Soil pH

Needs 5.5โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 5a

๐Ÿ“† Growing Season

113 days in San Miguel County

Growing Tips for Dill in San Miguel County

Direct sow Dill outdoors after May 31 in San Miguel County when soil has warmed and frost danger has passed.

Common pests for Dill in this region include carrot rust fly and parsleyworm. Use row covers early in the season and inspect plants weekly.

General growing tips

Direct sow in spring as dill has a taproot and dislikes transplanting. Succession sow for continuous leaf harvest. Allow some plants to flower for seeds and to attract beneficial insects.

Companion Planting

Good Companions

Avoid Planting Near

  • Carrots
  • Tomatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Dill in San Miguel County, CO?

San Miguel County is in Zone 5a with an average last frost of May 31. Plan your Dill planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is San Miguel County, CO?

San Miguel County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is May 31 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help San Miguel 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 San Miguel County, CO. Local conditions may vary. Last updated: April 2026.