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When to Plant Amaranth in Kern County, CA

Amaranth is an ancient grain crop with edible leaves and seeds, rich in protein and micronutrients. It thrives in warm conditions and is drought-tolerant once established.

Kern County, California is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 29, giving you a growing season of approximately 274 days.

At an elevation of 389 feet, Kern County receives approximately 16.9 inches of rainfall annually with predominantly loam soil. Summer highs average 102ยฐF, so Amaranth may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Amaranth successfully. Mulch heavily to conserve soil moisture.

Kern County, CA (Zone 9a) Year-round
274 days
Last Spring Frost February 28
274 growing days
First Fall Frost November 29

Kern County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (127 days to spare)
Start indoors: Jan 9 Transplant: Feb 27 🍅 Harvest: May 29 – Jul 17
Recommended (50%) ✓ Fits season (127 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🍅 Harvest: Jun 6 – Jul 25
Safe Start (90%) ✓ Fits season (109 days to spare)
Start indoors: Feb 24 Transplant: Apr 14 🍅 Harvest: Jul 14 – Sep 1

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
0.3″/week
You supply
1.3″/week
Watering frequency 2-3 times/week
Season total 3,060 gal / 100 sq ft
Drought risk

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

Amaranth needs ~2,782 GDD — county provides 7,287 GDD Excellent fit

Amaranth Planting Timeline โ€” Kern County, CA

Amaranth Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 โ€“ Jan 31
Transplant Outdoors March 7 Mar 7 โ€“ Mar 21
Direct Sow February 28 Feb 28 โ€“ Mar 21
Harvest June 6 Jun 6 โ€“ Jul 25

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

90โ€“120 days

Soil pH

6 โ€“ 7.5

USDA Zone

Zone 9a

Growing Season

274 days

Growing Tips for Kern County

Direct sow after last frost when soil is warm. Thin seedlings to 18 inches apart. Harvest leaves when young and tender; harvest seeds when flower heads begin to dry.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Level Up Your Garden

Frequently Asked Questions

When should I plant Amaranth in Kern County, CA?

Kern County is in Zone 9a with an average last frost of February 28. Plan your Amaranth planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Kern County, CA?

Kern County, California is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Kern County gardeners in Zone 9a organize planting dates, track what's growing, and never miss a planting window.

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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 Kern County, CA. Local conditions may vary. Last updated: April 2026.