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When to Plant Radicchio in Haines Borough, AK

Haines Borough, Alaska Zone 5b May

Your May game plan for Haines Borough, Alaska

May is a pivotal month for Haines Borough, Alaska gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 7
Avg. first frost September 29
Soil temp (4") 58°F
Watering High
Pest pressure Low
Daylight 16.6 hrs
  1. Move radicchio from tray to bed

    Your last frost (May 7) has passed. These warm-season crops can handle outdoor soil now.

To set up a strong June, finish these tasks
  • Starting indoors: radicchio

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Radicchio is an Italian chicory with stunning red and white leaves and a pleasantly bitter flavor. It forms tight heads and is used in salads, grilled, or braised.

Haines Borough, Alaska is in USDA Zone 5b. The average last spring frost is May 7 and the first fall frost is September 29, giving you a growing season of approximately 145 days.

At an elevation of 1,921 feet, Haines Borough receives approximately 57.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 68°F, so choose short-season varieties of Radicchio to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Radicchio root diseases.

Haines Borough, AK (Zone 5b) Short season
145 days
Last Spring Frost May 7
145 growing days
First Fall Frost September 29

Haines Borough Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (48 days to spare)
Start indoors: Mar 24 Transplant: Apr 28 🍅 Harvest: Jun 30 – Aug 4
Recommended (50%) ✓ Fits season (47 days to spare)
Start indoors: Apr 2 Transplant: May 7 🍅 Harvest: Jul 9 – Aug 13
Safe Start (90%) ✓ Fits season (45 days to spare)
Start indoors: Apr 23 Transplant: May 28 🍅 Harvest: Jul 30 – Sep 3

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 Haines Borough

How your county's soil matches Radicchio's growing requirements.

Soil pH

Your soil pH (4.9–6.4) is more acidic than Radicchio prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Radicchio.

Organic Matter

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

How to Plant Radicchio

0.5"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Succession Planting Radicchio

2
successive plantings in your 145-day season

Sow every 6.9 weeks. Last sowing by Jul 11 to harvest before frost.

For a dedicated fall crop, sow by Jul 21.

Plant Water Budget

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

Monthly Watering Guide for Radicchio

Radicchio needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Radicchio Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 2" 0" ❄️ Dormant
Apr 2" 0" ❄️ Dormant
May 3" 2.7" 0.3" 💧 Light watering
Jun 3" 4" 0" ✅ Rainfall sufficient
Jul 3" 8.1" 0" ✅ Rainfall sufficient
Aug 3" 8.5" 0" ✅ Rainfall sufficient
Sep 3" 10.6" 0" ✅ Rainfall sufficient
Oct 6.5" 0" ❄️ Dormant
Nov 4.1" 0" ❄️ Dormant
Dec 3.4" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Haines Borough). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Radicchio 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.

Radicchio needs ~70 GDD — county provides 145 GDD Excellent fit

Radicchio Planting Timeline — Haines Borough, AK

Radicchio Planting Calendar

Activity When Date Range
Start Indoors April 2 Apr 2 – Apr 16
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 23 Apr 23 – May 14
Harvest July 9 Jul 9 – Aug 13
Fall Sowing July 21 Jul 21 – Aug 4

Plant 0.5" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

60–80 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 5b

📆 Growing Season

145 days in Haines Borough

Growing Tips for Radicchio in Haines Borough

Direct sow Radicchio outdoors after May 07 in Haines Borough when soil has warmed and frost danger has passed.

Common pests for Radicchio in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

General growing tips

Start in late summer for fall harvest. The red color develops with cool nights and light frost. Harvest when heads are firm and compact.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Radicchio in Haines Borough, AK?

Haines Borough is in Zone 5b with an average last frost of May 7. Plan your Radicchio planting based on this frost date — see the calendar above for exact timing.

What planting zone is Haines Borough, AK?

Haines Borough, Alaska is in USDA Hardiness Zone 5b. The average last spring frost is May 7 and first fall frost is September 29.

🌱

Your Haines Borough Garden Planner — Free

A 24-page printable planner built for Haines Borough (Zone 5b). 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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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Haines Borough, AK. Local conditions may vary. Last updated: May 2026.

Sources & credits

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