When to Plant Squash (Summer) in Maricopa County, AZ
Top priorities for Maricopa County, Arizona gardeners in May
Welcome to May in Zone 9b. These are the moves that will have the biggest impact on your growing season.
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Bring in the squash (summer)
Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.
Summer squash includes zucchini, yellow crookneck, and pattypan varieties that are harvested young and tender. They are prolific producers in warm weather.
Maricopa County, Arizona is in USDA Zone 9b. The average last spring frost is January 31 and the first fall frost is December 6, giving you a growing season of approximately 309 days.
At an elevation of 4,014 feet, Maricopa County receives approximately 12.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 108°F, so Squash (Summer) may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Squash (Summer) will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Squash (Summer) successfully. Mulch heavily to conserve soil moisture.
Maricopa County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.2-8.5
Drainage
Well Drained
Plant 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 Maricopa County
How your county's soil matches Squash (Summer)'s growing requirements.
Soil pH
Your soil pH (7.2–8.5) is more alkaline than Squash (Summer) prefers (6.0–7.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in Maricopa County warms quickly in spring but drains fast. Squash (Summer) will need more frequent watering and regular compost additions to retain nutrients.
Organic Matter
Organic matter is low (0.7%). Add 2-3 inches of compost before planting Squash (Summer).
How to Plant Squash (Summer)
Succession Planting Squash (Summer)
Sow every 5.1 weeks. Last sowing by Oct 02 to harvest before frost.
Plant Water Budget
Water stress score is 10/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Squash (Summer)
Squash (Summer) needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Squash (Summer) Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Feb | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
| Mar | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Apr | 4.3" | 0.5" | 3.8" | 🚿 Regular watering |
| May | 4.3" | 0.3" | 4" | 🚿 Regular watering |
| Jun | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jul | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Aug | 4.3" | 2.3" | 2" | 💧 Light watering |
| Sep | 4.3" | 1.9" | 2.4" | 🚿 Regular watering |
| Oct | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
| Nov | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Dec | 4.3" | 0.8" | 3.5" | 🚿 Regular watering |
Water needs are for active growing months only (Jan–Dec in Maricopa County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Squash (Summer) 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.
Squash (Summer) Planting Timeline — Maricopa County, AZ
Squash (Summer) Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 3 | Jan 3 – Jan 17 |
| Transplant Outdoors | February 7 | Feb 7 – Feb 21 |
| Direct Sow | January 31 | Jan 31 – Feb 21 |
| Harvest | March 28 | Mar 28 – May 30 |
Plant 1" deep · 30" apart · Rows 42" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | Harvest |
| April | Harvest |
| May | Harvest |
| June | — |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · 2-3 times/week
📅 Days to Maturity
45–65 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_alkaline
🗺️ USDA Zone
Zone 9b
📆 Growing Season
309 days in Maricopa County
Growing Tips for Squash (Summer) in Maricopa County
Direct sow Squash (Summer) outdoors after January 31 in Maricopa County when soil has warmed and frost danger has passed.
Sandy soil in Maricopa County dries quickly — mulch Squash (Summer) with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 108°F in Maricopa County, provide afternoon shade for Squash (Summer) and water deeply in the morning.
Your generous 310.0-day season in Maricopa County allows multiple plantings of Squash (Summer). Sow every 22.0 days for continuous harvest.
Common pests for Squash (Summer) in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Direct sow after last frost on mounds. Harvest frequently when fruits are 6-8 inches for best texture. Check plants daily as they grow rapidly in summer heat.
Companion Planting
Good Companions
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Check more plant combinations with our Companion Planting Checker →
Squash (Summer) in Other Locations
Frequently Asked Questions
When should I plant Squash (Summer) in Maricopa County, AZ?
Maricopa County is in Zone 9b with an average last frost of January 31. Plan your Squash (Summer) planting based on this frost date — see the calendar above for exact timing.
What planting zone is Maricopa County, AZ?
Maricopa County, Arizona is in USDA Hardiness Zone 9b. The average last spring frost is January 31 and first fall frost is December 6.
Your Maricopa County Garden Planner — Free
A 24-page printable planner built for Maricopa 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.