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When to plant Spinach in Lake County, CO

Spinach planted in Lake County between June 7 and June 28 matures in 35–50 days — well before the August 30 first frost. A second sowing from June 21 to July 5 extends the harvest into fall.

When to Plant Spinach in Lake County, CO

Spinach

Spinach is a nutrient-packed cool-season green that grows quickly in spring and fall. It is rich in iron, vitamins, and antioxidants and excellent raw or cooked.

Lake County, Colorado is in USDA Zone 5a. The average last spring frost is June 21 and the first fall frost is August 30, giving you a growing season of approximately 70 days.

At an elevation of 7,687 feet, Lake County receives approximately 21.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Spinach to ensure they mature before fall.

Lake County, CO (Zone 5a) Very short season
70 days
Last Spring Frost June 21
70 growing days
First Fall Frost August 30

Lake County Soil Profile

Soil Type

Loam

Soil pH

6.6-8.2

Drainage

Well Drained

Monthly Watering Guide for Spinach

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

Month Spinach Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.1" 0" ❄️ Dormant
May 2.7" 0" ❄️ Dormant
Jun 4.3" 1.4" 2.9" 🚿 Regular watering
Jul 4.3" 2.1" 2.2" 🚿 Regular watering
Aug 4.3" 2.2" 2.1" 💧 Light watering
Sep 1.6" 0" ❄️ Dormant
Oct 2.1" 0" ❄️ Dormant
Nov 1.6" 0" ❄️ Dormant
Dec 1.2" 0" ❄️ Dormant

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

Spinach Planting Timeline — Lake County, CO

Spinach Planting Calendar

Activity When Date Range
Start Indoors May 17 May 17 – May 31
Transplant Outdoors June 21 Jun 21 – Jul 5
Direct Sow June 7 Jun 7 – Jun 28
Harvest July 26 Jul 26 – Sep 27
Fall Sowing June 21 Jun 21 – Jul 5

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

35–50 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

70 days in Lake County

Growing Tips for Lake County

Direct sow as soon as soil can be worked in spring. Plant in partial shade for summer crops to delay bolting. Succession plant every 2 weeks for continuous harvest.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Spinach Seeds
Life Cycle Annual
Pollination Wind Pollinated
How to Collect Let plants bolt. Harvest seed stalks when seeds turn tan.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Wind pollinated — isolate 1/2 mile for purity. Easy to let bolt in heat.

Frequently Asked Questions

When should I plant Spinach in Lake County, CO?

Lake County is in Zone 5a with an average last frost of June 21. Plan your Spinach planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, CO?

Lake County, Colorado is in USDA Hardiness Zone 5a. The average last spring frost is June 21 and first fall frost is August 30.

When should I plant Spinach in Lake County, CO?

In Lake County, CO, plant Spinach after the last frost (around June 21) and before the first frost (around August 30). Best results when soil holds above 50°F.

What growing zone is Lake County, CO for Spinach?

Lake County sits in USDA Zone 5a. Spinach grows reliably in zones 2a through 10b, so it's a good fit here.

Can Spinach grow in Lake County's climate?

Yes — Spinach grows well in Lake County's temperate climate. Lake County averages a 70-day frost-free season, with last frost around June 21 and first frost around August 30.

🌱

Your Lake County Garden Planner — Free

A 22-page printable planner built for Lake 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.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.