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When to Plant Sweet Potatoes in Roosevelt County, NM

Roosevelt County, New Mexico Zone 7b May

This month in Roosevelt County, New Mexico

Your garden in Roosevelt County, New Mexico is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost April 18
Avg. first frost October 22
Soil temp (4") 57°F
Watering Critical
Pest pressure Moderate
Daylight 13.8 hrs
  1. Harden off and plant sweet potatoes

    Your last frost (April 18) has passed. These warm-season crops can handle outdoor soil now.

Coming up in June — start thinking about
  • Starting indoors: sweet potatoes

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Sweet potatoes are a warm-season root crop that produces nutritious, sweet tubers in orange, white, and purple varieties. They need a long, hot growing season.

Roosevelt County, New Mexico is in USDA Zone 7b. The average last spring frost is April 18 and the first fall frost is October 22, giving you a growing season of approximately 187 days.

At an elevation of 3,802 feet, Roosevelt County receives approximately 18 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 89°F, providing good warmth for Sweet Potatoes during the growing season. Sandy soil warms quickly in spring — great for early planting — but Sweet Potatoes will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Sweet Potatoes successfully. Mulch heavily to conserve soil moisture.

Roosevelt County, NM (Zone 7b) Moderate season
187 days
Last Spring Frost April 18
187 growing days
First Fall Frost October 22

Roosevelt County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.2-8.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (31 days to spare)
Start indoors: Feb 23 Transplant: Apr 27 🍅 Harvest: Jul 27 – Sep 14
Recommended (50%) ✓ Fits season (33 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Aug 1 – Sep 19
Safe Start (90%) ✓ Fits season (37 days to spare)
Start indoors: Mar 14 Transplant: May 16 🍅 Harvest: Aug 15 – Oct 3

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 Roosevelt County

How your county's soil matches Sweet Potatoes's growing requirements.

Soil pH

Your soil pH (7.2–8.4) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Sweet Potatoes.

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Sweet Potatoes.

How to Plant Sweet Potatoes

1"
Planting Depth
15"
Between Plants
24"
Between Rows

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.4″/week
You supply
1.1″/week
Watering frequency 2-3 times/week
Season total 1,789 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Sweet Potatoes

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

Month Sweet Potatoes Needs Rainfall You Supplement Action
Jan 1.3" 0" ❄️ Dormant
Feb 0.9" 0" ❄️ Dormant
Mar 1.1" 0" ❄️ Dormant
Apr 4.3" 0.5" 3.8" 🚿 Regular watering
May 4.3" 0.3" 4" 🚿 Regular watering
Jun 4.3" 0.6" 3.7" 🚿 Regular watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 3.9" 0.4" 💧 Light watering
Sep 4.3" 2.6" 1.7" 💧 Light watering
Oct 4.3" 1.4" 2.9" 🚿 Regular watering
Nov 1" 0" ❄️ Dormant
Dec 1" 0" ❄️ Dormant

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

Sweet Potatoes 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.

Sweet Potatoes needs ~1,759 GDD — county provides 3,132 GDD Excellent fit

Sweet Potatoes Planting Timeline — Roosevelt County, NM

Sweet Potatoes Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 25 Apr 25 – May 16
Harvest August 1 Aug 1 – Sep 19

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June
July
August Harvest
September Harvest
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 5.5–6.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7b

📆 Growing Season

187 days in Roosevelt County

Growing Tips for Sweet Potatoes in Roosevelt County

Direct sow Sweet Potatoes outdoors after April 18 in Roosevelt County when soil has warmed and frost danger has passed.

Sandy soil in Roosevelt County dries quickly — mulch Sweet Potatoes with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Roosevelt County receives only 18" of rain annually. Sweet Potatoes needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Plant slips (rooted sprouts) after soil is thoroughly warm. Build raised mounds for better root development. Cure harvested roots at 80-85F for 10 days to develop sweetness.

Companion Planting

Good Companions

Avoid Planting Near

  • Squash Summer

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Potatoes in Roosevelt County, NM?

Roosevelt County is in Zone 7b with an average last frost of April 18. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Roosevelt County, NM?

Roosevelt County, New Mexico is in USDA Hardiness Zone 7b. The average last spring frost is April 18 and first fall frost is October 22.

🌱

Your Roosevelt County Garden Planner — Free

A 24-page printable planner built for Roosevelt County (Zone 7b). 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 Roosevelt 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.