When to Plant Sweet Potatoes in La Paz County, AZ
May in La Paz County, Arizona — your action list
If you only do a handful of things in the garden this May, make it these. They're sequenced around your zone's frost timing.
-
Pick sweet potatoes
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
June will be here before you know it — start on
- First harvests: sweet potatoes
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.
La Paz County, Arizona is in USDA Zone 9a. The average last spring frost is February 2 and the first fall frost is December 6, giving you a growing season of approximately 307 days.
At an elevation of 4,875 feet, La Paz County receives approximately 17.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 105°F, so Sweet Potatoes may need afternoon shade and extra watering during peak heat. 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.
La Paz County Soil Profile
Soil Type
Sandy Loam
Soil pH
7.2-8.3
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 La Paz County
How your county's soil matches Sweet Potatoes's growing requirements.
Soil pH
Your soil pH (7.2–8.3) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
Sandy soil in La Paz County warms quickly in spring but drains fast. Sweet Potatoes 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 Sweet Potatoes.
How to Plant Sweet Potatoes
Plant Water Budget
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 | 4.3" | 0.9" | 3.4" | 🚿 Regular watering |
| Mar | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Apr | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| May | 4.3" | 0.4" | 3.9" | 🚿 Regular watering |
| Jun | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Jul | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Aug | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Sep | 4.3" | 2.5" | 1.8" | 💧 Light watering |
| Oct | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Nov | 4.3" | 1" | 3.3" | 🚿 Regular watering |
| Dec | 4.3" | 1.2" | 3.1" | 🚿 Regular watering |
Water needs are for active growing months only (Feb–Dec in La Paz 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 Planting Timeline — La Paz County, AZ
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | December 22 | Dec 22 – Jan 5 |
| Transplant Outdoors | February 9 | Feb 9 – Feb 23 |
| Direct Sow | February 2 | Feb 2 – Feb 23 |
| Harvest | May 11 | May 11 – Jun 29 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors Direct Sow |
| March | — |
| April | — |
| May | Harvest |
| June | Harvest |
| July | — |
| August | — |
| September | — |
| October | — |
| November | — |
| December | Start Indoors |
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 9a
📆 Growing Season
307 days in La Paz County
Growing Tips for Sweet Potatoes in La Paz County
Direct sow Sweet Potatoes outdoors after February 02 in La Paz County when soil has warmed and frost danger has passed.
Sandy soil in La Paz 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.
With summer highs reaching 105°F in La Paz County, provide afternoon shade for Sweet Potatoes and water deeply in the morning.
La Paz County receives only 17" 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
Check more plant combinations with our Companion Planting Checker →
Sweet Potatoes in Other Locations
Frequently Asked Questions
When should I plant Sweet Potatoes in La Paz County, AZ?
La Paz County is in Zone 9a with an average last frost of February 2. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is La Paz County, AZ?
La Paz County, Arizona is in USDA Hardiness Zone 9a. The average last spring frost is February 2 and first fall frost is December 6.
Your La Paz County Garden Planner — Free
A 24-page printable planner built for La Paz County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.