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Kenai Peninsula Borough, AK — Planting Guide

Kenai Peninsula Borough, Alaska Zone 5a May

This month in Kenai Peninsula Borough, Alaska

Your Kenai Peninsula Borough, Alaska garden is entering a new phase. Here's what's on the schedule for May and why each task matters now.

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 basil, cucumber, and kale

    Pinch off the lowest leaves on each seedling before you plant — it reduces water loss while the roots catch up.

  2. Put basil, carrots, and cucumber seeds straight in the ground

    Your soil is 52°F — warm enough for these to germinate without babying.

  3. Collect radish, cress, and microgreens at their peak

    This is the payoff month. Bring a basket, bring a friend, and get into the beds.

To set up a strong June, finish these tasks
  • Transplants going out: alpine strawberries, aronia, and blackberries
  • Starting indoors: cucumber, kale, and lettuce
  • First harvests: lettuce, radish, and arugula

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Kenai Peninsula Borough 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 ft, Kenai Peninsula Borough receives approximately 55.7 in of rainfall annually. The predominant soil type is Silt Loam.

Based on 31 years of NOAA climate station data, the last frost date here varies by 30 days year to year — ranging from May 1 in warm years to June 1 in cold years. The growing season is trending longer by about 3.61 days per decade. Kenai Peninsula Borough scores 54/100 (Moderate) on the Microclimate Index.

🌡️ Zone

5a (°F to °F min)

❄️ Last Frost

May 17

🍂 First Frost

September 25

📅 Growing Season

131 days

⛰️ Elevation

1,824 ft

🌧️ Annual Rainfall

55.7 in

Kenai Peninsula Borough, AK Short season
131 days
Last Spring Frost May 17
131 growing days
First Fall Frost September 25

Monthly Watering Calendar

When you'll need to water your garden — based on average monthly rainfall vs. the ~1 inch/week most gardens need.

1"/wk 0" 2.5" 5.1" 7.6" 10.1" Jan 3.2" Feb 2.4" Mar 2" +2.8" Apr 1.5" +2" May 2.3" Jun 3.8" Jul 7.6" Aug 8.3" Sep 10.1" Oct 7" Nov 4.3" Dec 3.2"
Rainfall sufficient Supplemental water needed Heavy watering required - - - 1"/week garden need
View detailed monthly data
MonthAvg RainfallRainy DaysExtra Water NeededWatering Effort
Jan 3.2 in 6 days None
Feb 2.4 in 5 days None
Mar 2 in 5 days None
Apr 1.5 in 4 days 2.8 in High
May 2.3 in 5 days 2 in High
Jun 3.8 in 8 days 0.5 in Low
Jul 7.6 in 11 days Low
Aug 8.3 in 13 days Low
Sep 10.1 in 15 days Low
Oct 7 in 12 days Low
Nov 4.3 in 9 days None
Dec 3.2 in 6 days None

Annual total: 55.7 in. Water needs vary by crop — tomatoes need ~1.2"/week while herbs like rosemary need only 0.3"/week. Check individual plant pages for crop-specific water budgets that factor in your county's rainfall and soil drainage.

Kenai Peninsula Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-6.8

Drainage

Well Drained

Frost Risk Probability

Based on 31 years of NOAA weather station data from 3 stations

Too early frost risk Safe to Plant May 17 → Sep 25 131 frost-free days Protect crops frost returns Apr May Jun Jul Aug Sep Oct Nov Safe: Jun 1 Protect by: Oct 10

Beginners: Plant frost-sensitive crops (tomatoes, peppers, squash) after the "Safe" date on the left. Harvest or cover them before the "Protect by" date on the right. Hardy crops (lettuce, peas, kale) can go in the yellow transition zones.

How to read this table: "Conservative" means you're safe from frost 9 out of 10 years — best for beginners and frost-sensitive crops. "Average year" is the typical date. "Aggressive" means only 1 in 10 years is that warm — experienced gardeners with frost protection can try these dates.

Planting Strategy Last Spring Frost First Fall Frost Frost-Free Days
Conservative (safest) Jun 1 Oct 10 131 days
Cautious May 23 Sep 29 129 days
Average year May 17 Sep 25 131 days
Optimistic May 12 Sep 18 129 days
Aggressive (risky) May 1 Sep 1 123 days
📊
How predictable are frost dates here?

Not very — frost dates can vary by ±30 days year-to-year. Use the "Conservative" row in the table below, and keep row covers handy for surprise late frosts.

🌱
Is the growing season changing?

Yes — growing seasons are getting longer here (about 3.6 days per decade). Spring is arriving earlier than it used to. Good news for gardeners.

Gardening Difficulty Score

54 Moderate
Frost Timing Risk
10.0/10
Drought Risk
1.5/10
Soil Difficulty
0.0/10
Altitude Challenge
1.7/10
Climate Shift
10.0/10
Rainfall Challenge
4.3/10

Kenai Peninsula Borough presents some gardening challenges. Choose adapted varieties and plan around frost dates.

Zone 5a Frost Countdown
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Loading...
Last Frost: May 17 First Frost: Sep 25

Local Gardening Help in Kenai Peninsula Borough

Free expert help is closer than you think. Your county's cooperative extension office connects you with trained gardeners, soil testing labs, and local programs — all specific to Kenai Peninsula Borough's climate and soil.

County Extension Office

Kenai Peninsula Borough University of Alaska Fairbanks Cooperative Extension Extension Office

Phone: 907-474-5211

Visit Extension Office Website →

Extension offices are run by land-grant universities and funded by the USDA. Their advice is free, research-based, and tailored to your county's specific conditions.

Master Gardener Program

Free gardening help from trained volunteers

Master Gardeners are community volunteers who complete 40–60 hours of university horticultural training. They answer gardening questions, diagnose plant problems, and offer workshops — all free.

Find Master Gardeners in AK →

Many extension offices run a Master Gardener hotline where you can call or email with photos of plant problems for free diagnosis.

Soil Testing

Available through your extension office

Before amending your soil, get it tested. Your extension office offers soil testing (typically $10–$25) that tells you exact pH, nutrient levels, and amendment recommendations specific to what you want to grow.

Request a Soil Test →

Services Available in Kenai Peninsula Borough

Soil testing Cold-climate gardening Food preservation
Finding local nurseries & garden centers in Kenai Peninsula Borough

Why Buy Local

Local nurseries carry plants that are proven to grow in your area. Staff can give you advice specific to Kenai Peninsula Borough's soil and climate that big-box stores can't. Plants from local growers are typically hardier because they're already acclimated to your zone.

How to Find Them

Search for "nurseries near Kenai Peninsula Borough AK" or "garden center Kenai Peninsula Borough" on Google Maps. Also check with your extension office — they often maintain lists of reputable local nurseries and plant sales.

Community gardens & gardening groups

Community gardens are a great way to learn from experienced gardeners in your area, especially if you're limited on space. Search "community garden Kenai Peninsula Borough AK" or check your extension office and local parks department. Facebook groups like "Kenai Peninsula Borough Gardeners" or "Alaska Gardening" are also excellent for local advice and plant swaps.

What to Plant After Your Harvest

After your first crops finish, use the remaining frost-free days to grow a second round.

After Spinach (harvest ends Aug 23) 33 days until frost
After Carrots (harvest ends Aug 23) 33 days until frost
After Dill (harvest ends Aug 23) 33 days until frost
After New Zealand Spinach (harvest ends Aug 23) 33 days until frost
Show 6 more succession options
After Cilantro (harvest ends Aug 23) 33 days until frost
After Kohlrabi (harvest ends Aug 9) 47 days until frost
After Mustard Greens (harvest ends Aug 23) 33 days until frost
After Crookneck Squash (harvest ends Aug 16) 40 days until frost
After Scallions (harvest ends Aug 9) 47 days until frost
After Turnip (harvest ends Aug 2) 54 days until frost

Sunlight & Day Length

Monthly daylight hours and peak sun — critical for onion varieties, photoperiod-sensitive plants, and solar garden planning.

Longest Day

18.5 hours

Summer solstice daylight

Shortest Day

5.5 hours

Winter solstice daylight

Peak Sun Hours

8.9 hr/day peak (summer)

Peak sun hours (green dashed line below) account for cloud cover — this is the usable direct sunlight your garden actually receives. Most vegetables need 6+ peak sun hours.

14hr 12hr 0h 5h 10h 15h 20h Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Daylight hours (sunrise to sunset) Peak sun hours (direct sunlight after cloud cover) ▪ Gold zone = long day (14+ hr) ▪ Blue zone = short day (<12 hr)

Onion tip: Your long summer days (14+ hours) support long-day onion varieties like Walla Walla, Sweet Spanish, and Ailsa Craig.

View detailed monthly data
MonthDaylight HoursPeak Sun HoursDay Length
January 6.3 hr 2 hr Short day
February 8.8 hr 3.2 hr Short day
March 11.3 hr 4.7 hr Short day
April 14.2 hr 6.6 hr Long day
May 16.8 hr 7.4 hr Long day
June 18.5 hr 8.9 hr Long day
July 17.8 hr 8.5 hr Long day
August 15.4 hr 6.8 hr Long day
September 12.5 hr 4.9 hr Neutral
October 9.7 hr 3.3 hr Short day
November 7.1 hr 1.9 hr Short day
December 5.5 hr 1.4 hr Short day

Peak sun hours factor in typical cloud cover — use these for solar panel and shade-planning calculations.

Soil Temperature & Composting Calendar

Monthly soil temps tell you when to plant warm-season crops, and when your compost pile is actively working.

Plant Warm Crops When

Soil reaches 60°F+

Soil warm enough from Jun through Sep.

Best Month to Compost

Jul

Microbial activity peaks when soil is warm.

Active Composting

6 months

Solid season. Piles go dormant in winter.

60°F 70°F 23° 45° 68° 90° Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
4" depth 8" depth - - - 60°F (corn, beans) - - - 70°F (tomatoes, peppers)
View detailed monthly data
MonthSoil 4" DeepSoil 8" DeepCompost ActivityTime to Finish
Jan 19°F 27°F ❄️ Dormant ~36 weeks
Feb 18°F 25°F ❄️ Dormant ~36 weeks
Mar 25°F 29°F ❄️ Dormant ~36 weeks
Apr 38°F 38°F ❄️ Dormant ~36 weeks
May 52°F 48°F ♻️ Active ~14 weeks
Jun 63°F 59°F ♻️ Active ~14 weeks
Jul 72°F 66°F 🔥 Peak ~8 weeks
Aug 72°F 68°F 🔥 Peak ~8 weeks
Sep 65°F 65°F 🔥 Peak ~8 weeks
Oct 52°F 56°F ♻️ Active ~14 weeks
Nov 37°F 45°F ❄️ Dormant ~36 weeks
Dec 23°F 32°F ❄️ Dormant ~36 weeks

Highlighted rows = soil 60°F+ (safe for warm-season transplants). Compost finishes fastest during peak activity months.

Pest & Disease Pressure in Kenai Peninsula Borough

Computed from local climate patterns — warmer, humid conditions increase pest generations and fungal disease risk.

Insect Pest Pressure

5.3 / 10

Moderate — common pests appear but manageable with monitoring.

Disease Risk

5.9 / 10

Moderate — watch for mildew and blight during wet periods.

Seasonal Risk

Spring Low
Summer High
Fall Low
Winter Low
View 5 common pests in your area
PestRisk LevelPeak Months
Aphids Moderate May, Jun, Jul, Aug
Japanese beetles Moderate Jun, Jul, Aug
Squash bugs Low Jun, Jul, Aug
Tomato hornworms Moderate Jul, Aug
Cabbage loopers Low May, Jun, Jul, Aug
Organic pest management tips
  • Use row covers on susceptible crops during peak pest months
  • Apply neem oil preventatively every 7-14 days during active pest season
  • Interplant with strong-scented herbs (basil, marigold) to confuse pests
  • Hand-pick larger pests (beetles, caterpillars) in early morning when they're sluggish
  • Practice crop rotation — never plant the same family in the same spot within 3 years

Cover Crops for Kenai Peninsula Borough

Cover crops protect bare soil, fix nitrogen, suppress weeds, and improve soil structure — with county-specific planting dates.

Spring Cover Crops (3 options) — Build soil before the main growing season
Crop Plant By Terminate N-Fixing Soil Benefit
Buckwheat May 21 Jul 17 Rapid growth, attracts pollinators, suppresses weeds
Sorghum-sudan grass May 24 Jul 17 Massive biomass, breaks compaction, suppresses nematodes
White clover Apr 18 Jul 24 ✓ Yes Living mulch, fixes nitrogen, permanent ground cover
Summer Cover Crops (1 options) — Fill gaps and suppress weeds between plantings
Crop Plant By Terminate N-Fixing Soil Benefit
Sunflowers Jun 2 Sep 11 Deep roots break compaction, attract pollinators and beneficial insects
Fall Cover Crops (6 options) — Plant after harvest to protect soil over winter
Crop Plant By Terminate N-Fixing Soil Benefit
Austrian winter peas Jul 23 May 3 ✓ Yes Fixes nitrogen, good for heavy clay soils
Daikon radish Aug 12 Apr 26 Deep taproot breaks compaction, excellent for clay soils
Hairy vetch Jul 2 May 3 ✓ Yes Excellent nitrogen fixer, good for depleted soils
Oats Aug 15 Apr 26 Quick biomass, winterkills in cold zones — no spring tillage needed
Winter rye Jun 28 May 3 Suppresses weeds, prevents erosion, breaks up compacted soil
Winter wheat Jun 28 May 3 Erosion control, weed suppression, good biomass

Wind & Microclimate

Wind dries soil, stresses plants, and affects frost patterns. Understanding your exposure helps with garden placement.

Seasonal Wind Speed

Spring: 12 mph   Summer: 9 mph

Fall: 10 mph   Winter: 13 mph

Prevailing wind: N. Moderate wind — consider a temporary windbreak for young seedlings.

Windbreak Benefit

6.8/10

Moderately beneficial — a simple fence or trellis can protect delicate crops from wind stress.

Frost Pocket Risk

Moderate

Some terrain variation (768 ft range). Garden on slopes or higher ground if possible to avoid late-season frost pockets.

Rainwater Harvesting Potential

How much water you can collect, when to collect it, and what size system you need for your garden.

Annual Collection

27,760 gal

Per 1,000 sq ft of roof area (at 80% collection efficiency)

Recommended Setup

6 rain barrels (55 gal each)

For a typical 500 sq ft garden. Serious collectors: consider a 1,500 gal tank.

Legal Status

Unrestricted

Rainwater harvesting is fully legal in your state with no restrictions.

Best Collection Months

Jul, Aug, Sep, Oct

Highest rainfall months — your barrels will fill up quickly during these months.

Months to Draw From Storage

Mar, Apr, May

Dry months when you'll rely on stored water — size your storage for this gap.

Rainwater collection tips for your area
  • Your county receives approximately 55.7 inches of rain per year
  • A 1,000 sq ft roof can collect roughly 27,760 gallons annually
  • Rainwater harvesting is fully legal in your state
  • Your area gets ample rainfall — even small barrels make a big difference
  • Consider a rain garden to handle overflow during heavy rainfall months

Soil & Growing Conditions in Kenai Peninsula Borough

Soil Type

Silt Loam

Soil pH 5.2–6.8 · Moderately Well Drained drainage

Raised beds strongly recommended here — native soil drainage or texture limits in-ground options.

Watering Needs

Drought stress: 1.5/10

Kenai Peninsula Borough has very low drought pressure. Natural rainfall usually meets garden needs — water only during extended dry spells.

Season Tips

131-day frost-free season

Start warm-season crops indoors and focus on short-season varieties. Cold frames extend your season by 3–4 weeks in fall.

Your Free Printable Garden Planner

Plan every bed, every planting, every harvest — in one place. This 24-page printable includes your zone's planting calendar, a month-by-month task list, a seed inventory tracker, a harvest log, and succession-planting charts. Built to print, write in, and actually use all season.

Instant PDF download. No spam, unsubscribe any time.

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Recommended for Your Garden

🧪
Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

📏
Digital pH Meter $10-20

Get instant, accurate soil pH readings to fine-tune your amendments.

🍂
Organic Compost $8-30

Boost soil fertility and structure with rich, well-aged organic compost.

🥬 Vegetables to Grow in Kenai Peninsula Borough

106 vegetables that grow well in Zone 5a with planting dates for Kenai Peninsula Borough.

Show all 106 vegetables with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Acorn Squash Apr 12 May 24 May 31 Aug 23 – Sep 27 80–100
Amaranth Mar 22 May 24 May 31 Aug 30 – Oct 18 90–120
Arugula Apr 12 May 3 May 17 Jun 21 – Aug 23 30–50
Asparagus May 31 730–1095
Beets May 3 Jun 28 – Jul 26 50–70
Belgian Endive Apr 12 May 3 May 17 Sep 6 – Nov 1 110–150
Bitter Melon Mar 22 May 24 May 31 Aug 2 – Sep 13 60–90
Black Beans May 24 Aug 23 – Oct 11 90–120
Bok Choy Apr 12 May 3 May 17 Jun 28 – Aug 2 40–60
Broccoli Apr 12 May 3 May 17 Jul 19 – Aug 30 60–90
Broccoli Rabe Apr 12 May 3 May 17 Jun 28 – Aug 2 40–60
Brussels Sprouts Apr 12 May 3 May 17 Aug 16 – Oct 11 90–130
Butternut Squash Apr 12 May 24 May 31 Aug 30 – Oct 4 85–110
Cabbage Apr 12 May 3 May 17 Jul 19 – Sep 13 60–100
Calabash Mar 22 May 24 May 31 Aug 23 – Oct 18 80–120
Carrots May 3 Jul 5 – Aug 9 60–80
Cauliflower Apr 12 May 3 May 17 Jul 12 – Sep 13 55–100
Celeriac Apr 12 May 3 May 17 Aug 30 – Oct 4 100–120
Celery Apr 12 May 3 May 17 Aug 9 – Oct 4 80–120
Celtuce Apr 12 May 3 May 17 Jul 19 – Aug 30 60–90
Chard Apr 12 May 3 May 17 Jul 12 – Aug 30 50–60
Chickpeas Apr 12 May 3 May 17 Aug 9 – Sep 20 80–110
Chicory Apr 12 May 3 May 17 Jul 19 – Aug 30 60–85
Chinese Cabbage Apr 12 May 3 May 17 Jul 12 – Aug 9 50–70
Christmas Lima Beans Mar 22 May 24 May 31 Aug 23 – Sep 27 80–100
Collard Greens Apr 12 May 3 May 17 Jul 12 – Sep 13 55–75
Corn May 24 Jul 26 – Sep 20 60–100
Cowpeas May 24 Jul 26 – Sep 6 60–90
Cress Apr 12 May 3 May 17 May 31 – Jun 21 14–21
Crookneck Squash Apr 12 May 24 May 31 Jul 19 – Aug 16 45–60
Crosne May 3 Oct 4 – Oct 18 150–200
Cucumber Apr 12 May 24 May 31 Jul 26 – Sep 20 50–70
Daikon May 3 Jun 28 – Jul 26 50–70
Delicata Squash Apr 12 May 24 May 31 Aug 23 – Sep 27 80–100
Edamame May 24 Aug 9 – Sep 20 75–100
Eggplant Mar 8 May 24 May 31 Aug 9 – Oct 11 65–85
Endive Apr 12 May 3 May 17 Jul 5 – Aug 9 45–65
Escarole Apr 12 May 3 May 17 Jul 12 – Aug 9 50–70
Fava Beans Apr 12 May 3 May 17 Aug 2 – Sep 13 75–100
Fennel Mar 22 May 24 May 31 Aug 2 – Sep 13 60–90
Garlic 90–240
Green Beans May 24 Jul 19 – Sep 13 50–65
Horseradish May 31 Oct 4 – Nov 15 120–180
Hot Peppers Mar 8 May 24 May 31 Aug 9 – Nov 15 70–120
Hubbard Squash Apr 12 May 24 May 31 Sep 13 – Oct 18 100–120
Kabocha Apr 12 May 24 May 31 Aug 30 – Sep 27 85–100
Kai Lan Apr 12 May 3 May 17 Jul 5 – Aug 2 45–60
Kale Apr 12 May 3 May 17 Jul 12 – Sep 6 50–70
Kidney Beans May 24 Aug 23 – Sep 27 85–110
Kohlrabi Apr 12 May 3 May 17 Jul 5 – Aug 9 45–65
Komatsuna Apr 12 May 3 May 17 Jun 21 – Jul 26 35–50
Leeks Apr 12 May 3 May 17 Aug 16 – Nov 1 90–150
Lentils Apr 12 May 3 May 17 Aug 9 – Sep 20 80–110
Lettuce Apr 12 May 3 May 17 Jun 21 – Aug 30 30–60
Lima Beans May 24 Jul 26 – Sep 6 60–90
Mache Apr 12 May 3 May 17 Jun 28 – Aug 2 40–60
Melon Apr 12 May 24 May 31 Aug 9 – Sep 27 70–100
Microgreens Apr 12 May 3 May 17 May 24 – Jun 21 7–21
Mitsuba Apr 12 May 3 May 10 Jul 5 – Aug 30 50–70
Mizuna Apr 12 May 3 May 17 Jun 21 – Jul 19 30–45
Mustard Greens Apr 12 May 3 May 17 Jun 21 – Aug 23 30–50
Napa Cabbage Apr 12 May 3 May 17 Jul 12 – Aug 16 55–75
New Zealand Spinach Mar 22 May 24 May 31 Jul 26 – Aug 23 55–70
Okra Mar 22 May 24 May 31 Jul 26 – Sep 20 50–65
Onion Apr 12 May 3 May 17 Aug 16 – Oct 4 90–120
Pac Choi Apr 12 May 3 May 17 Jun 28 – Jul 26 40–55
Parsnip May 3 Aug 16 – Sep 27 100–130
Patty Pan Squash Apr 12 May 24 May 31 Jul 19 – Aug 16 45–60
Peas Apr 12 May 3 May 17 Jul 12 – Sep 6 55–70
Peppers Mar 8 May 24 May 31 Aug 2 – Oct 11 60–90
Pole Beans Mar 22 May 24 May 31 Jul 26 – Sep 20 55–70
Potatoes Mar 22 May 24 May 31 Aug 9 – Oct 18 70–120
Pumpkin Apr 12 May 24 May 31 Aug 30 – Oct 18 85–120
Purslane Apr 12 May 3 May 17 Jun 28 – Aug 2 40–60
Radicchio Apr 12 May 3 May 17 Jul 19 – Aug 23 60–80
Radish May 3 May 31 – Jun 21 22–35
Rhubarb Jun 7 365–730
Romanesco Apr 12 May 3 May 17 Aug 2 – Sep 13 75–100
Rutabaga May 3 Jul 26 – Aug 30 80–100
Salsify May 3 Aug 16 – Sep 27 100–130
Savoy Cabbage Apr 12 May 3 May 17 Jul 26 – Sep 20 70–110
Scallions Apr 12 May 3 May 17 Jul 12 – Aug 9 50–70
Scarlet Runner Beans Mar 22 May 24 May 31 Aug 2 – Sep 6 60–80
Shallot Apr 12 May 3 May 17 Aug 16 – Oct 4 90–120
Shiso Mar 29 May 24 May 31 Jul 26 – Sep 20 50–70
Snap Peas Mar 22 May 24 May 31 Jul 26 – Sep 20 55–70
Snow Peas Apr 12 May 3 May 17 Jul 12 – Sep 6 50–65
Soybeans May 24 Aug 16 – Oct 11 80–120
Spaghetti Squash Apr 12 May 24 May 31 Aug 30 – Sep 27 85–100
Spinach Apr 12 May 3 May 17 Jun 21 – Aug 23 35–50
Squash (Summer) Apr 12 May 24 May 31 Jul 19 – Sep 20 45–65
Squash (Winter) Apr 12 May 24 May 31 Aug 23 – Oct 18 80–120
Sunchoke May 31 Sep 20 – Nov 15 110–150
Sunflower Mar 22 May 24 May 31 Aug 9 – Sep 27 70–100
Sweet Corn May 24 Jul 26 – Sep 6 60–90
Sweet Potatoes Mar 22 May 24 May 31 Aug 30 – Oct 18 90–120
Tatsoi Apr 12 May 3 May 17 Jun 21 – Jul 26 35–50
Tomatillo Mar 22 May 24 May 31 Aug 2 – Oct 11 60–85
Tomatoes Mar 22 May 24 May 31 Aug 2 – Oct 11 60–85
Turnip May 3 Jun 14 – Jul 19 40–60
Watercress Apr 12 May 3 May 17 Jun 28 – Aug 2 40–60
Watermelon Apr 12 May 24 May 31 Aug 9 – Sep 27 70–100
Wax Beans May 24 Jul 19 – Sep 13 50–65
Winter Melon Mar 22 May 24 May 31 Aug 30 – Oct 18 90–120
Yard Long Beans Mar 22 May 24 May 31 Jul 26 – Sep 6 55–80
Zucchini Apr 12 May 24 May 31 Jul 19 – Sep 13 45–60

🍓 Fruits to Grow in Kenai Peninsula Borough

27 fruits that grow well in Zone 5a with planting dates for Kenai Peninsula Borough.

Show all 27 fruits with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Alpine Strawberries Jun 7 Sep 6 – Nov 22 90–180
Aronia Jun 7 730–1095
Blackberries Jun 7 365–730
Blueberries Jun 7 730–1095
Boysenberries Jun 7 365–730
Cantaloupe Jun 7 Aug 16 – Sep 20 70–90
Che Fruit Jun 7 1095–1825
Cranberries Jun 7 730–1095
Currants Jun 7 730–1095
Elderberries Jun 7 730–1095
Goji Berries Jun 7 730–1095
Gooseberries Jun 7 730–1095
Grapes Jun 7 730–1095
Ground Cherry Jun 7 Aug 16 – Oct 11 65–80
Hardy Kiwi Jun 7 1095–1825
Haskaps Jun 7 730–1095
Honeydew Jun 7 Aug 30 – Oct 11 80–110
Jostaberry Jun 7 730–1095
Lingonberries Jun 7 730–1095
Medlar Jun 7 1095–1825
Mulberries Jun 7 730–1825
Pawpaw Jun 7 1095–2555
Persimmon Jun 7 1095–2555
Quince Jun 7 1095–1825
Raspberries Jun 7 365–730
Serviceberries Jun 7 730–1095
Strawberries Jun 7 Sep 6 – Nov 22 90–365

🌿 Herbs to Grow in Kenai Peninsula Borough

37 herbs that grow well in Zone 5a with planting dates for Kenai Peninsula Borough.

Show all 37 herbs with planting dates
Plant Start Indoors Direct Sow Transplant Harvest Days to Maturity
Angelica Apr 12 May 3 May 10 365–730
Anise Apr 12 May 3 May 10 Aug 9 – Oct 25 90–120
Basil Mar 29 May 24 May 31 Jul 26 – Sep 27 50–75
Bee Balm May 24 Aug 23 – Nov 8 90–120
Borage Apr 12 May 3 May 10 Jul 5 – Aug 23 50–60
Caraway Apr 12 May 3 May 10 365–450
Catnip May 24 Jul 26 – Sep 27 60–80
Chamomile Apr 12 May 3 May 10 Jul 12 – Sep 20 60–90
Chervil Apr 12 May 3 May 10 Jun 21 – Aug 23 40–60
Chives May 24 Jul 26 – Oct 4 60–90
Cilantro Apr 12 May 3 May 10 Jun 21 – Aug 23 40–60
Comfrey May 24 Jul 26 – Oct 4 60–90
Cumin Apr 12 May 3 May 10 Aug 23 – Oct 25 100–120
Dill Apr 12 May 3 May 10 Jun 21 – Aug 23 40–60
Echinacea May 24 Sep 27 – Nov 8 120–180
Epazote Mar 29 May 24 May 31 Jul 19 – Sep 13 45–60
Fennel (herb) Apr 12 May 3 May 10 Jul 12 – Sep 20 60–90
Feverfew May 24 Aug 23 – Nov 8 90–120
Garlic Chives May 24 Jul 26 – Oct 4 60–90
Horehound May 24 Aug 9 – Oct 4 75–90
Hyssop May 24 Aug 2 – Oct 4 70–90
Lavender May 24 Aug 23 – Nov 8 90–200
Lemon Balm May 24 Jul 26 – Sep 13 60–70
Lemon Thyme May 24 Aug 2 – Oct 4 70–90
Lovage May 24 Aug 2 – Oct 4 70–90
Mint May 24 Jul 26 – Oct 4 60–90
Oregano May 24 Jul 26 – Oct 4 60–90
Parsley Apr 12 May 3 May 10 Jul 12 – Sep 13 60–80
Rue May 24 Aug 2 – Oct 4 70–90
Sage May 24 Aug 9 – Oct 4 75–90
Savory May 24 Jul 19 – Sep 13 50–70
Sorrel Apr 12 May 3 May 10 Jun 21 – Aug 23 40–60
Tarragon May 24 Jul 26 – Oct 4 60–90
Thai Basil Mar 29 May 24 May 31 Jul 26 – Sep 27 50–75
Thyme May 24 Aug 2 – Oct 4 70–90
Valerian May 24 Sep 27 – Nov 8 120–180
Yarrow May 24 Aug 23 – Nov 8 90–120
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Monthly Planting Guide for Kenai Peninsula Borough

Gardening Guides & Resources

Helpful guides from The Ultimate Homestead to improve your garden in Kenai Peninsula Borough.

Frequently Asked Questions

What planting zone is Kenai Peninsula Borough, AK?

Kenai Peninsula Borough is in USDA Hardiness Zone 5a. This zone classification determines which perennial plants survive winter and sets the baseline for frost timing across the county.

When is the last frost in Kenai Peninsula Borough, AK?

Based on 31 years of NOAA weather station data, the median last spring frost in Kenai Peninsula Borough falls around May 17. In 8 out of 10 years, last frost lands between May 1 and June 1 — a 30-day window of variability. Use June 1 as your conservative safe-to-plant date for frost-sensitive crops.

When is the first fall frost in Kenai Peninsula Borough, AK?

The median first fall frost in Kenai Peninsula Borough arrives around September 25. In cold years it can arrive as early as September 1; in mild years as late as October 10. Harvest or protect frost-sensitive crops — tomatoes, peppers, basil, squash — before this date.

How long is the growing season in Kenai Peninsula Borough?

Kenai Peninsula Borough has a frost-free growing season of approximately 131 days. Focus on short-season varieties and start warm-season crops indoors 6–8 weeks before last frost. Climate records show the growing season is trending longer by about 3.61 days per decade.

What is the soil like in Kenai Peninsula Borough for gardening?

Kenai Peninsula Borough has predominantly Silt Loam soil with a pH range of 5.2–6.8 and Moderately Well Drained drainage. The native soil conditions make raised beds a particularly good investment here — they let you control drainage and fertility independent of the ground soil.

What is grown commercially in Kenai Peninsula Borough?

Kenai Peninsula Borough has commercial agriculture that includes Hay, Cattle, Potatoes. These crops reflect the local climate and soil conditions — what succeeds commercially often translates well to home gardens in the same area.

Is Kenai Peninsula Borough a good location for home gardening?

Kenai Peninsula Borough scores 54/100 (Moderate) on our Microclimate Index, which combines frost reliability, drought pressure, soil challenge, elevation risk, and long-term climate trend. Conditions here are moderate — most common crops grow well with standard timing and care.

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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.

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The Gardener's Encyclopedia to Companion Planting

The Gardener's Encyclopedia to Companion Planting

$27 $293 value

The pairings that make vegetables, herbs, and flowers grow better — and the ones that quietly wreck a bed.

  • Proven pairings for 200+ vegetables, herbs, flowers, and fruits
  • Full seed-starting + planting schedule with timing and spacing
  • Bonus: square-foot gardening guide + printable seasonal planners
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Seed Saving & Storage Guide

Seed Saving & Storage Guide

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Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.

  • 200 plants, step-by-step: life cycle, pollination type, isolation
  • Exact temperature + humidity ranges that keep seeds viable
  • Bonus: searchable Google Sheets tracker + custom GPT assistant
Save a lifetime of seed money →
Composting Guide for Homesteaders

Composting Guide for Homesteaders

$27 $210 value

Turn kitchen scraps and yard waste into compost that actually feeds the garden — instead of a pile that smells, attracts pests, and never breaks down.

  • 14 sections on composting methods, soil science, and troubleshooting
  • The 7-step hot-compost system from start to finish
  • Bonus tools: troubleshooting chart, safety guide, monitoring log
Start composting today →

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA GHCN-D daily station data (1994–2024) from 3 weather stations in or near Kenai Peninsula Borough (31 years of records). Frost dates represent 50% probability averages; local conditions vary by elevation and microclimate. 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.