When to Plant Potatoes in Kenai Peninsula Borough, AK
Your May gardening checklist
May is a pivotal month for Kenai Peninsula Borough, Alaska gardens. Focus on these tasks first and you'll set up the rest of the season for success.
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Transplant potatoes outside
Plant tomatoes deep — bury the stem up to the first true leaves to grow extra roots. Everything else goes in at the same depth it grew in the tray.
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Scatter potatoes into prepared beds
Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.
Potatoes are a versatile staple crop that produces tubers underground. They come in hundreds of varieties with varying colors, textures, and maturity dates.
Kenai Peninsula Borough, Alaska is in USDA Zone 5a. The average last spring frost is May 17 and the first fall frost is September 25, giving you a growing season of approximately 131 days.
At an elevation of 1,824 feet, Kenai Peninsula Borough receives approximately 55.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 60°F, so choose short-season varieties of Potatoes to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Potatoes root diseases.
Kenai Peninsula Borough Soil Profile
Soil Type
Silt Loam
Soil pH
5.2-6.8
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 Kenai Peninsula Borough
How your county's soil matches Potatoes's growing requirements.
Soil pH
Your soil pH (5.2–6.8) overlaps with Potatoes's range (5.0–6.5), though not a perfect match.
Soil Texture
The silt loam soil in Kenai Peninsula Borough is excellent for Potatoes — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (6.6%) — Potatoes will thrive.
How to Plant Potatoes
Succession Planting Potatoes
Sow every 8 weeks. Last sowing by May 28 to harvest before frost.
Plant Water Budget
Monthly Watering Guide for Potatoes
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 | Potatoes Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.2" | 0" | ❄️ Dormant |
| Feb | — | 2.4" | 0" | ❄️ Dormant |
| Mar | — | 2" | 0" | ❄️ Dormant |
| Apr | — | 1.5" | 0" | ❄️ Dormant |
| May | 4.3" | 2.3" | 2" | 💧 Light watering |
| Jun | 4.3" | 3.8" | 0.5" | 💧 Light watering |
| Jul | 4.3" | 7.6" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 8.3" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 10.1" | 0" | ✅ Rainfall sufficient |
| Oct | — | 7" | 0" | ❄️ Dormant |
| Nov | — | 4.3" | 0" | ❄️ Dormant |
| Dec | — | 3.2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (May–Sep in Kenai Peninsula Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
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.
Potatoes Planting Timeline — Kenai Peninsula Borough, AK
Potatoes Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 22 | Mar 22 – Apr 5 |
| Transplant Outdoors | May 31 | May 31 – Jun 14 |
| Direct Sow | May 24 | May 24 – Jun 14 |
| Harvest | August 9 | Aug 9 – Oct 18 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow |
| July | — |
| August | Harvest |
| September | Harvest |
| October | Harvest |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Natural rainfall sufficient
📅 Days to Maturity
70–120 days
🧪 Soil pH
Needs 5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 5a
📆 Growing Season
131 days in Kenai Peninsula Borough
Growing Tips for Potatoes in Kenai Peninsula Borough
Direct sow Potatoes outdoors after May 17 in Kenai Peninsula Borough when soil has warmed and frost danger has passed.
Your 131.0-day growing season in Kenai Peninsula Borough is tight for Potatoes (70.0-120.0 days to maturity). Start indoors and choose early-maturing varieties.
Common pests for Potatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.
General growing tips
Plant seed potatoes (not grocery store potatoes) 4 inches deep in spring. Hill soil around stems as plants grow to prevent greening. Stop watering when plants die back.
Recommended Potatoes Varieties for Kenai Peninsula Borough
Early-maturing potatoes for your season
Companion Planting
Good Companions
Avoid Planting Near
Check more plant combinations with our Companion Planting Checker →
Potatoes in Other Locations
Frequently Asked Questions
When should I plant Potatoes in Kenai Peninsula Borough, AK?
Kenai Peninsula Borough is in Zone 5a with an average last frost of May 17. Plan your Potatoes planting based on this frost date — see the calendar above for exact timing.
What planting zone is Kenai Peninsula Borough, AK?
Kenai Peninsula Borough, Alaska is in USDA Hardiness Zone 5a. The average last spring frost is May 17 and first fall frost is September 25.
Your Kenai Peninsula Borough Garden Planner — Free
A 24-page printable planner built for Kenai Peninsula Borough (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.