When to plant Shallot in Pima County, AZ
For Shallot in Pima County, the safe spring window opens around March 11 and closes around April 1. Last expected frost is April 1, first fall frost November 9, giving a 222-day growing season. A second sowing from September 14 to September 28 extends the harvest into fall.
When to Plant Shallot in Pima County, AZ
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- First harvests: shallot
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.
Pima County, Arizona is in USDA Zone 9b. The average last spring frost is April 1 and the first fall frost is November 9, giving you a growing season of approximately 222 days.
At an elevation of 4,327 feet, Pima County receives approximately 14.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 103°F, so Shallot may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — 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.
Pima County Soil Profile
Soil Type
Sandy Loam
Soil pH
6.8-8.3
Drainage
Well Drained
Shallot Planting Risk Windows
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 Pima County
How your county's soil matches Shallot's growing requirements.
Soil pH
Your soil pH (6.8–8.3) is more alkaline than Shallot prefers (6.0–7.0). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Pima County warms quickly in spring but drains fast. Shallot will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Shallot.
Organic Matter
Organic matter is low (0.9%). Add 2-3 inches of compost before planting Shallot.
How to Plant Shallot
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Shallot Water Budget
Water stress score is 10/10 — 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 | — | 0.9" | 0" | ❄️ Dormant |
| Feb | — | 0.8" | 0" | ❄️ Dormant |
| Mar | — | 0.7" | 0" | ❄️ Dormant |
| Apr | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| Jul | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Aug | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Sep | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Oct | 4.3" | 1.4" | 2.9" | 🚿 Regular watering |
| Nov | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Dec | — | 0.9" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Pima County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 Planting Timeline — Pima County, AZ
Shallot Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 4 | Mar 4 – Mar 18 |
| Transplant Outdoors | April 1 | Apr 1 – Apr 15 |
| Direct Sow | March 11 | Mar 11 – Apr 1 |
| Harvest | July 1 | Jul 1 – Aug 19 |
| Fall Sowing | September 14 | Sep 14 – Sep 28 |
Plant 1" deep · 6" apart · Rows 12" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors Direct Sow |
| April | Transplant Outdoors Direct Sow |
| May | — |
| June | — |
| July | Harvest |
| August | Harvest |
| September | Fall Sowing |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
90–120 days
🧪 Soil pH
Needs 6–7 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
222 days in Pima County
Growing Tips for Shallot in Pima County
Direct sow Shallot outdoors after April 01 in Pima County when soil has warmed and frost danger has passed.
Sandy soil in Pima County dries quickly — mulch Shallot with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 103°F in Pima County, provide afternoon shade for Shallot and water deeply in the morning.
Common pests for Shallot in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.
Pima County receives only 14" of rain annually. Shallot needs consistent moisture — 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
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Shallot in Other Locations
Frequently Asked Questions
When should I plant Shallot in Pima County, AZ?
Pima County is in Zone 9b with an average last frost of April 1. Plan your Shallot planting based on this frost date — see the calendar above for exact timing.
What planting zone is Pima County, AZ?
Pima County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is April 1 and first fall frost is November 9.
When should I plant Shallot in Pima County, AZ?
In Pima County, AZ, plant Shallot after the last frost (around April 1) and before the first frost (around November 9). Best results when soil holds above 50°F.
What growing zone is Pima County, AZ for Shallot?
Pima County sits in USDA Zone 9b. Shallot grows reliably in zones 4a through 10b, so it's a good fit here.
Can Shallot grow in Pima County's climate?
Yes — Shallot grows well in Pima County's temperate climate. Pima County averages a 222-day frost-free season, with last frost around April 1 and first frost around November 9.
Your Pima County Garden Planner — Free
A 22-page printable planner built for Pima County (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.