Blog

When to Plant Hyssop in Ketchikan Gateway Borough, AK

Ketchikan Gateway Borough, Alaska Zone 7b May

Top priorities for Ketchikan Gateway Borough, Alaska gardeners in May

We've pulled the most time-sensitive tasks for Ketchikan Gateway Borough, Alaska this May and put them front and centre. Tackle them in order.

Avg. last frost April 25
Avg. first frost October 19
Soil temp (4") 64°F
Watering High
Pest pressure Moderate
Daylight 15.9 hrs
  1. Transplant hyssop outside

    Pick a cloudy afternoon or evening to plant. Less transplant shock, and your seedlings will barely blink.

Instant PDF download. No spam, unsubscribe any time.

Hyssop is a semi-evergreen perennial herb with intense blue flower spikes that attract bees and butterflies. It has a minty, slightly bitter flavor used in liqueurs and teas.

Ketchikan Gateway Borough, Alaska is in USDA Zone 7b. The average last spring frost is April 25 and the first fall frost is October 19, giving you a growing season of approximately 177 days.

At an elevation of 1,212 feet, Ketchikan Gateway Borough receives approximately 57.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 65°F, so choose short-season varieties of Hyssop to ensure they mature before fall. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Hyssop root diseases.

Ketchikan Gateway Borough, AK (Zone 7b) Moderate season
177 days
Last Spring Frost April 25
177 growing days
First Fall Frost October 19

Ketchikan Gateway Borough Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (35 days to spare)
Transplant: Apr 25 🍅 Harvest: Jul 4 – Sep 5
Recommended (50%) ✓ Fits season (37 days to spare)
Transplant: May 2 🍅 Harvest: Jul 11 – Sep 12
Safe Start (90%) ✓ Fits season (33 days to spare)
Transplant: May 20 🍅 Harvest: Jul 29 – Sep 30

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 Ketchikan Gateway Borough

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

Soil pH

Your soil pH (5.0–6.7) is more acidic than Hyssop prefers (6.0–8.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Hyssop prefers dry conditions but your soil drains poorly. Use raised beds or mounded rows to prevent root rot.

Organic Matter

Organic matter is excellent (5.9%) — Hyssop will thrive.

How to Plant Hyssop

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Hyssop

2
successive plantings in your 177-day season

Sow every 8 weeks. Last sowing by Jul 21 to harvest before frost.

Plant Water Budget

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

Monthly Watering Guide for Hyssop

Hyssop needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Hyssop Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 2.6" 0" ❄️ Dormant
Mar 1.8" 0" ❄️ Dormant
Apr 2.2" 2" 0.2" 💧 Light watering
May 2.2" 2.4" 0" ✅ Rainfall sufficient
Jun 2.2" 4.5" 0" ✅ Rainfall sufficient
Jul 2.2" 6.6" 0" ✅ Rainfall sufficient
Aug 2.2" 9.5" 0" ✅ Rainfall sufficient
Sep 2.2" 11" 0" ✅ Rainfall sufficient
Oct 2.2" 6.6" 0" ✅ Rainfall sufficient
Nov 3.8" 0" ❄️ Dormant
Dec 3.9" 0" ❄️ Dormant

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

Hyssop 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.

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

Hyssop Planting Timeline — Ketchikan Gateway Borough, AK

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors May 2 May 2 – May 16
Harvest July 11 Jul 11 – Sep 12

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

70–90 days

🧪 Soil pH

Needs 6–8 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7b

📆 Growing Season

177 days in Ketchikan Gateway Borough

Growing Tips for Hyssop in Ketchikan Gateway Borough

Direct sow Hyssop outdoors after April 25 in Ketchikan Gateway Borough when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors or direct sow in spring. Prune back in early spring to encourage bushy growth. Hyssop is drought-tolerant once established and thrives in poor soil.

Companion Planting

Good Companions

Avoid Planting Near

  • Radish

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Hyssop in Ketchikan Gateway Borough, AK?

Ketchikan Gateway Borough is in Zone 7b with an average last frost of April 25. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Ketchikan Gateway Borough, AK?

Ketchikan Gateway Borough, Alaska is in USDA Hardiness Zone 7b. The average last spring frost is April 25 and first fall frost is October 19.

🌱

Your Ketchikan Gateway Borough Garden Planner — Free

A 24-page printable planner built for Ketchikan Gateway Borough (Zone 7b). 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 Ketchikan Gateway 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.