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When to Plant Cucumber in Kenai Peninsula Borough, AK

Kenai Peninsula Borough, Alaska Zone 5a May

May in Kenai Peninsula Borough, Alaska — 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.

Avg. last frost May 17
Avg. first frost September 25
Soil temp (4") 52°F
Watering High
Pest pressure Low
Daylight 16.8 hrs
  1. Time to transplant cucumber

    Frost risk is low now in Kenai Peninsula Borough, Alaska. If you've been covering beds overnight, you can stop.

  2. Direct-sow cucumber

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

June will be here before you know it — start on
  • Starting indoors: cucumber

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Cucumbers are a warm-season vine crop available in slicing and pickling varieties. They are prolific producers when given warmth, moisture, and a trellis to climb.

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 Cucumber to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Cucumber root diseases.

Kenai Peninsula Borough, AK (Zone 5a) Short season
131 days
Last Spring Frost May 17
131 growing days
First Fall Frost September 25

Kenai Peninsula Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (3 days to spare)
Start indoors: Apr 7 Transplant: May 26 🍅 Harvest: Jul 21 – Sep 15
Recommended (50%) ✓ Fits season (5 days to spare)
Start indoors: Apr 12 Transplant: May 31 🍅 Harvest: Jul 26 – Sep 20
Safe Start (90%) ✓ Fits season (5 days to spare)
Start indoors: Apr 27 Transplant: Jun 15 🍅 Harvest: Aug 10 – Oct 5

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 Cucumber's growing requirements.

Soil pH

Your soil pH (5.2–6.8) overlaps with Cucumber's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Kenai Peninsula Borough is excellent for Cucumber — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (6.6%) — Cucumber will thrive.

How to Plant Cucumber

0.5"
Planting Depth
24"
Between Plants
48"
Between Rows

Succession Planting Cucumber

3
successive plantings in your 131-day season

Sow every 5.7 weeks. Last sowing by Jul 17 to harvest before frost.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
1.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Cucumber

Cucumber needs approximately 1.5 inches of water per week (6.5" per month). Here's how your county's rainfall compares month by month.

Month Cucumber 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 6.5" 2.3" 4.2" 🚿 Regular watering
Jun 6.5" 3.8" 2.7" 💧 Light watering
Jul 6.5" 7.6" 0" ✅ Rainfall sufficient
Aug 6.5" 8.3" 0" ✅ Rainfall sufficient
Sep 6.5" 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.

Cucumber 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.

Cucumber needs ~0 GDD — county provides 0 GDD May not mature

Cucumber Planting Timeline — Kenai Peninsula Borough, AK

Cucumber Planting Calendar

Activity When Date Range
Start Indoors April 12 Apr 12 – Apr 26
Transplant Outdoors May 31 May 31 – Jun 14
Direct Sow May 24 May 24 – Jun 14
Harvest July 26 Jul 26 – Sep 20

Plant 0.5" deep · 24" apart · Rows 48" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.5"/week · Natural rainfall sufficient

📅 Days to Maturity

50–70 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 5a

📆 Growing Season

131 days in Kenai Peninsula Borough

Growing Tips for Cucumber in Kenai Peninsula Borough

Direct sow Cucumber outdoors after May 17 in Kenai Peninsula Borough when soil has warmed and frost danger has passed.

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

General growing tips

Direct sow after last frost or start indoors 3 weeks early. Provide a trellis for vining types to save space and improve air circulation. Harvest frequently to encourage production.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes
  • Sage

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Cucumber in Kenai Peninsula Borough, AK?

Kenai Peninsula Borough is in Zone 5a with an average last frost of May 17. Plan your Cucumber 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.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Kenai Peninsula Borough, AK. 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.