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When to plant Dill in Summit County, CO

In Summit County, plant Dill in spring between June 2 and June 23, once soil temps hold above 50°F. Summit County's last frost averages June 16, so time plantings around the expected last-frost window for best survival. For a fall crop, sow between June 26 and July 10 — roughly 40–60 days before the first frost on September 4.

When to Plant Dill in Summit County, CO

Dill

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.

Summit County, Colorado is in USDA Zone 5a. The average last spring frost is June 16 and the first fall frost is September 4, giving you a growing season of approximately 80 days.

At an elevation of 7,005 feet, Summit County receives approximately 17.5 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Dill to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Dill successfully. Mulch heavily to conserve soil moisture.

Summit County, CO (Zone 5a) Very short season
80 days
Last Spring Frost June 16
80 growing days
First Fall Frost September 4

Summit County Soil Profile

Soil Type

Loam

Soil pH

6.8-8

Drainage

Well Drained

Monthly Watering Guide for Dill

Dill needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Dill Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.7" 0" ❄️ Dormant
May 1.8" 0" ❄️ Dormant
Jun 4.3" 1.3" 3" 🚿 Regular watering
Jul 4.3" 1.5" 2.8" 🚿 Regular watering
Aug 4.3" 1.9" 2.4" 🚿 Regular watering
Sep 4.3" 1.3" 3" 🚿 Regular watering
Oct 1.6" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Summit County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Dill Planting Timeline — Summit County, CO

Dill Planting Calendar

Activity When Date Range
Start Indoors May 12 May 12 – May 26
Transplant Outdoors June 9 Jun 9 – Jun 23
Direct Sow June 2 Jun 2 – Jun 23
Harvest July 21 Jul 21 – Sep 22
Fall Sowing June 26 Jun 26 – Jul 10

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

40–60 days

🧪 Soil pH

Needs 5.5–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

80 days in Summit County

Growing Tips for Summit County

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 Summit County, CO?

Summit County is in Zone 5a with an average last frost of June 16. Plan your Dill planting based on this frost date — see the calendar above for exact timing.

What planting zone is Summit County, CO?

Summit County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 16 and first fall frost is September 4.

When should I plant Dill in Summit County, CO?

In Summit County, CO, plant Dill after the last frost (around June 16) and before the first frost (around September 4). Best results when soil holds above 50°F.

What growing zone is Summit County, CO for Dill?

Summit County sits in USDA Zone 5a. Dill grows reliably in zones 2a through 11b, so it's a good fit here.

Can Dill grow in Summit County's climate?

Yes — Dill grows well in Summit County's temperate climate. Summit County averages a 80-day frost-free season, with last frost around June 16 and first frost around September 4.

🌱

Your Summit County Garden Planner — Free

A 22-page printable planner built for Summit County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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

Sources & credits

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