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When to Plant Acorn Squash in San Juan County, NM

San Juan County, New Mexico Zone 7a May

May to-do list for San Juan County, New Mexico

Welcome to May in Zone 7a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost May 12
Avg. first frost October 6
Soil temp (4") 32°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Plant out acorn squash

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

  2. Put acorn squash seeds straight in the ground

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Coming up in June — start thinking about
  • Starting indoors: acorn squash

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Acorn squash is a small winter squash with dark green, ribbed skin and mildly sweet orange flesh. It is perfect for stuffing and roasting as individual servings.

San Juan County, New Mexico is in USDA Zone 7a. The average last spring frost is May 12 and the first fall frost is October 6, giving you a growing season of approximately 147 days.

At an elevation of 8,301 feet, San Juan County receives approximately 14.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 87°F, providing good warmth for Acorn Squash during the growing season. Sandy soil warms quickly in spring — great for early planting — but Acorn Squash will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Acorn Squash successfully. Mulch heavily to conserve soil moisture.

San Juan County, NM (Zone 7a) Short season
147 days
Last Spring Frost May 12
147 growing days
First Fall Frost October 6
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San Juan County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.5

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (11 days to spare)
Start indoors: Apr 7 Transplant: May 19 🍅 Harvest: Aug 11 – Sep 15
Recommended (50%) ✓ Fits season (14 days to spare)
Start indoors: Apr 14 Transplant: May 26 🍅 Harvest: Aug 18 – Sep 22
Safe Start (90%) ✓ Fits season (8 days to spare)
Start indoors: May 5 Transplant: Jun 16 🍅 Harvest: Sep 8 – Oct 13

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 San Juan County

How your county's soil matches Acorn Squash's growing requirements.

Soil pH

Your soil pH (7.3–8.5) is more alkaline than Acorn Squash prefers (5.5–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in San Juan County warms quickly in spring but drains fast. Acorn Squash will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Acorn Squash.

Organic Matter

Organic matter is low (0.9%). Add 2-3 inches of compost before planting Acorn Squash.

How to Plant Acorn Squash

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Succession Planting Acorn Squash

2
successive plantings in your 147-day season

Sow every 9.1 weeks. Last sowing by Jun 28 to harvest before frost.

Plant Water Budget

Plant needs
1.1″/week
Rainfall provides
0.4″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,604 gal / 100 sq ft
Drought risk

Water stress score is 10/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Acorn Squash

Acorn Squash needs approximately 1.1 inches of water per week (4.8" per month). Here's how your county's rainfall compares month by month.

Month Acorn Squash Needs Rainfall You Supplement Action
Jan 1.1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 0.8" 0" ❄️ Dormant
Apr 0.5" 0" ❄️ Dormant
May 4.8" 0.3" 4.5" 🚿 Regular watering
Jun 4.8" 0.5" 4.3" 🚿 Regular watering
Jul 4.8" 2.5" 2.3" 💧 Light watering
Aug 4.8" 2.6" 2.2" 💧 Light watering
Sep 4.8" 2.2" 2.6" 🚿 Regular watering
Oct 4.8" 1.3" 3.5" 🚿 Regular watering
Nov 0.8" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (May–Oct in San Juan County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Acorn Squash 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.

Acorn Squash needs ~1,372 GDD — county provides 2,241 GDD Excellent fit

Acorn Squash Planting Timeline — San Juan County, NM

Acorn Squash Planting Calendar

Activity When Date Range
Start Indoors April 14 Apr 14 – Apr 28
Transplant Outdoors May 26 May 26 – Jun 9
Direct Sow May 19 May 19 – Jun 9
Harvest August 18 Aug 18 – Sep 22

Plant 1" deep · 30" apart · Rows 42" apart

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.1"/week · 2-3 times/week

📅 Days to Maturity

80–100 days

🧪 Soil pH

Needs 5.5–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

147 days in San Juan County

Growing Tips for Acorn Squash in San Juan County

Direct sow Acorn Squash outdoors after May 12 in San Juan County when soil has warmed and frost danger has passed.

Sandy soil in San Juan County dries quickly — mulch Acorn Squash with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Common pests for Acorn Squash in this region include squash vine borer and cucumber beetles. Use row covers early in the season and inspect plants weekly.

San Juan County receives only 14" of rain annually. Acorn Squash needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Harvest when the ground spot turns orange and the skin is hard. Acorn squash has a shorter storage life than butternut, lasting about 2 months.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Acorn Squash in San Juan County, NM?

San Juan County is in Zone 7a with an average last frost of May 12. Plan your Acorn Squash planting based on this frost date — see the calendar above for exact timing.

What planting zone is San Juan County, NM?

San Juan County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is May 12 and first fall frost is October 6.

🌱

Your San Juan County Garden Planner — Free

A 24-page printable planner built for San Juan County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 San Juan County, NM. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.