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When to Plant Tomatoes in Klamath County, OR

Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Klamath County, Oregon is in USDA Zone 6a. The average last spring frost is June 13 and the first fall frost is September 21, giving you a growing season of approximately 100 days.

At an elevation of 142 feet, Klamath County receives approximately 48.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83ยฐF, so choose short-season varieties of Tomatoes to ensure they mature before fall.

Klamath County, OR (Zone 6a) Short season
100 days
Last Spring Frost June 13
100 growing days
First Fall Frost September 21

Klamath County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 4 Transplant: Jun 13 🍅 Harvest: Aug 15 – Oct 24
Recommended (50%) ✗ May not fit
Start indoors: Apr 18 Transplant: Jun 27 🍅 Harvest: Aug 29 – Nov 7
Safe Start (90%) ✗ May not fit
Start indoors: May 1 Transplant: Jul 10 🍅 Harvest: Sep 11 – Nov 20

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
2.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Tomatoes needs ~888 GDD — county provides 1,225 GDD Excellent fit

Tomatoes Planting Timeline โ€” Klamath County, OR

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors April 18 Apr 18 โ€“ May 2
Transplant Outdoors June 27 Jun 27 โ€“ Jul 11
Direct Sow June 20 Jun 20 โ€“ Jul 11
Harvest August 29 Aug 29 โ€“ Nov 7

Plant 0.5" deep ยท 24" apart ยท Rows 36" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

60โ€“85 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 6a

Growing Season

100 days

Growing Tips for Klamath County

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Level Up Your Garden

๐ŸŒพ Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35ยฐF, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Klamath County, OR?

Klamath County is in Zone 6a with an average last frost of June 13. Plan your Tomatoes planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Klamath County, OR?

Klamath County, Oregon is in USDA Hardiness Zone 6a. The average last spring frost is June 13 and first fall frost is September 21.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Klamath County gardeners in Zone 6a 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 Klamath County, OR. Local conditions may vary. Last updated: April 2026.