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When to Plant Cress in Kern County, CA

Garden cress is one of the fastest-growing edibles, producing peppery sprouts in as little as two weeks. It is excellent for microgreens and garnishes.

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 Cress may need afternoon shade and extra watering during peak heat. With low rainfall, drip irrigation is essential for growing Cress 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 (239 days to spare)
Start indoors: Jan 23 Transplant: Feb 20 🍅 Harvest: Mar 6 – Mar 27
Recommended (50%) ✓ Fits season (239 days to spare)
Start indoors: Jan 31 Transplant: Feb 28 🍅 Harvest: Mar 14 – Apr 4
Safe Start (90%) ✓ Fits season (221 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🍅 Harvest: Apr 21 – May 12

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 Kern County

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

Soil pH

Your soil pH (6.2โ€“7.7) overlaps with Cress's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Cress.

Organic Matter

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

How to Plant Cress

0.5"
Planting Depth
2"
Between Plants
6"
Between Rows

Fall planting: Sow 8 weeks before your first frost date for a fall harvest.

Succession Planting Cress

24
successive plantings in your 274-day season

Sow every 1.6 weeks. Last sowing by Nov 08 to harvest before frost.

For a dedicated fall crop, sow by Oct 04.

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

Monthly Watering Guide for Cress

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

Month Cress Needs Rainfall You Supplement Action
Jan โ€” 3.9" 0" โ„๏ธ Dormant
Feb 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Mar 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Apr 4.3" 1.2" 3.1" ๐Ÿšฟ Regular watering
May 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
Jun 4.3" 0.1" 4.2" ๐Ÿšฟ Regular watering
Jul 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Aug 4.3" 0" 4.3" ๐Ÿšฟ Regular watering
Sep 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Oct 4.3" 0.7" 3.6" ๐Ÿšฟ Regular watering
Nov 4.3" 1.7" 2.6" ๐Ÿšฟ Regular watering
Dec โ€” 2.8" 0" โ„๏ธ Dormant

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

Cress 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.

Cress needs ~464 GDD — county provides 7,287 GDD Excellent fit

Cress Planting Timeline โ€” Kern County, CA

Cress Planting Calendar

Activity When Date Range
Start Indoors January 31 Jan 31 โ€“ Feb 14
Transplant Outdoors February 28 Feb 28 โ€“ Mar 14
Direct Sow February 7 Feb 7 โ€“ Feb 28
Harvest March 14 Mar 14 โ€“ Apr 4
Fall Sowing October 4 Oct 4 โ€“ Oct 18

Plant 0.5" deep ยท 2" apart ยท Rows 6" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

14โ€“21 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 9a

๐Ÿ“† Growing Season

274 days in Kern County

Growing Tips for Cress in Kern County

Direct sow Cress outdoors after February 28 in Kern County when soil has warmed and frost danger has passed.

With summer highs reaching 102ยฐF in Kern County, provide afternoon shade for Cress and water deeply in the morning.

Your generous 275.0-day season in Kern County allows multiple plantings of Cress. Sow every 7.0 days for continuous harvest.

Common pests for Cress in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Kern County receives only 17" of rain annually. Cress needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Sow seeds thickly on moist soil or paper towels. Keep moist and harvest when 2-3 inches tall. Succession sow every few days for continuous supply. Grows well indoors year-round.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cress in Kern County, CA?

Kern County is in Zone 9a with an average last frost of February 28. Plan your Cress 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.