When to Plant Sweet Potatoes in Laramie County, WY
May in Laramie County, Wyoming — your action list
Welcome to May in Zone 5b. These are the moves that will have the biggest impact on your growing season.
-
Seed sweet potatoes outdoors
These tolerate cool soil, so you're not gambling by sowing now.
To set up a strong June, finish these tasks
- Transplants going out: 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.
Laramie County, Wyoming is in USDA Zone 5b. The average last spring frost is May 19 and the first fall frost is September 24, giving you a growing season of approximately 128 days.
At an elevation of 6,153 feet, Laramie County receives approximately 19.3 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Sweet Potatoes to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Sweet Potatoes successfully. Mulch heavily to conserve soil moisture.
Laramie County Soil Profile
Soil Type
Loam
Soil pH
6.5-8.2
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 Laramie County
How your county's soil matches Sweet Potatoes's growing requirements.
Soil pH
Your soil pH (6.5–8.2) is more alkaline than Sweet Potatoes prefers (5.5–6.5). Add sulfur or peat moss to lower pH.
Soil Texture
The loam soil in Laramie County is excellent for Sweet Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Sweet Potatoes.
Organic Matter
Organic matter is moderate (2.3%). Annual compost additions will help Sweet Potatoes.
How to Plant Sweet Potatoes
Plant Water Budget
Water stress score is 8/10 — 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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.4" | 0" | ❄️ Dormant |
| Mar | — | 1.6" | 0" | ❄️ Dormant |
| Apr | — | 1.9" | 0" | ❄️ Dormant |
| May | 4.3" | 2.1" | 2.2" | 🚿 Regular watering |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 1.8" | 2.5" | 🚿 Regular watering |
| Aug | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | — | 1.7" | 0" | ❄️ Dormant |
| Nov | — | 1.2" | 0" | ❄️ Dormant |
| Dec | — | 1.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Laramie 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 — Laramie County, WY
Sweet Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 24 | Mar 24 – Apr 7 |
| Transplant Outdoors | June 2 | Jun 2 – Jun 16 |
| Direct Sow | May 26 | May 26 – Jun 16 |
| Harvest | September 1 | Sep 1 – Oct 20 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | — |
| September | Harvest |
| October | Harvest |
| 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 5b
📆 Growing Season
128 days in Laramie County
Growing Tips for Sweet Potatoes in Laramie County
Direct sow Sweet Potatoes outdoors after May 19 in Laramie County when soil has warmed and frost danger has passed.
Your 128.0-day growing season in Laramie County is tight for Sweet Potatoes (90.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.
Laramie County receives only 19" 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 Laramie County, WY?
Laramie County is in Zone 5b with an average last frost of May 19. Plan your Sweet Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Laramie County, WY?
Laramie County, Wyoming is in USDA Hardiness Zone 5b. The average last spring frost is May 19 and first fall frost is September 24.
Your Laramie County Garden Planner — Free
A 24-page printable planner built for Laramie County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.