Blog

When to Plant Shallot in Yuma County, AZ

Shallots are a gourmet allium prized for their complex, sweet, and mild flavor. Each bulb multiplies into a cluster, making them easy and rewarding to grow.

Yuma County, Arizona is in USDA Zone 10a. The average last spring frost is February 10 and the first fall frost is December 1, giving you a growing season of approximately 294 days.

At an elevation of 4,781 feet, Yuma County receives approximately 9.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 92ยฐF, providing good warmth for Shallot during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Shallot will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Shallot successfully. Mulch heavily to conserve soil moisture.

Yuma County, AZ (Zone 10a) Year-round
294 days
Last Spring Frost February 10
294 growing days
First Fall Frost December 1

Yuma County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.9-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (156 days to spare)
Start indoors: Jan 6 Transplant: Feb 3 🍅 Harvest: May 5 – Jun 23
Recommended (50%) ✓ Fits season (154 days to spare)
Start indoors: Jan 13 Transplant: Feb 10 🍅 Harvest: May 12 – Jun 30
Safe Start (90%) ✓ Fits season (144 days to spare)
Start indoors: Feb 9 Transplant: Mar 9 🍅 Harvest: Jun 8 – Jul 27

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 Yuma County

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

Soil pH

Your soil pH (6.9โ€“8.4) is more alkaline than Shallot prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Yuma County warms quickly in spring but drains fast. Shallot will need more frequent watering and regular compost additions to retain nutrients.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Shallot.

How to Plant Shallot

1"
Planting Depth
6"
Between Plants
12"
Between Rows

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

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.1″/week
You supply
1.0″/week
Watering frequency 2-3 times/week
Season total 2,729 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Shallot

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

Month Shallot Needs Rainfall You Supplement Action
Jan โ€” 0.6" 0" โ„๏ธ Dormant
Feb 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
Mar 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
Apr 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
May 4.3" 0.2" 4.1" ๐Ÿšฟ Regular watering
Jun 4.3" 0.3" 4" ๐Ÿšฟ Regular watering
Jul 4.3" 1.8" 2.5" ๐Ÿšฟ Regular watering
Aug 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Sep 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Oct 4.3" 0.8" 3.5" ๐Ÿšฟ Regular watering
Nov 4.3" 0.5" 3.8" ๐Ÿšฟ Regular watering
Dec 4.3" 0.6" 3.7" ๐Ÿšฟ Regular watering

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

Shallot 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.

Shallot needs ~1,995 GDD — county provides 5,605 GDD Excellent fit

Shallot Planting Timeline โ€” Yuma County, AZ

Shallot Planting Calendar

Activity When Date Range
Start Indoors January 13 Jan 13 โ€“ Jan 27
Transplant Outdoors February 10 Feb 10 โ€“ Feb 24
Direct Sow January 20 Jan 20 โ€“ Feb 10
Harvest May 12 May 12 โ€“ Jun 30
Fall Sowing October 6 Oct 6 โ€“ Oct 20

Plant 1" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 2-3 times/week

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 10a

๐Ÿ“† Growing Season

294 days in Yuma County

Growing Tips for Shallot in Yuma County

Direct sow Shallot outdoors after February 10 in Yuma County when soil has warmed and frost danger has passed.

Sandy soil in Yuma County dries quickly โ€” mulch Shallot with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Common pests for Shallot in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

Yuma County receives only 9" of rain annually. Shallot needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant sets in fall for spring harvest or early spring for summer harvest. Mulch heavily if overwintering. Harvest when tops brown and dry, then cure for storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Shallot in Yuma County, AZ?

Yuma County is in Zone 10a with an average last frost of February 10. Plan your Shallot planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Yuma County, AZ?

Yuma County, Arizona is in USDA Hardiness Zone 10a. The average last spring frost is February 10 and first fall frost is December 1.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Yuma County gardeners in Zone 10a 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 Yuma County, AZ. Local conditions may vary. Last updated: April 2026.