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When to Plant Hyssop in Bowman County, ND

Bowman County, North Dakota Zone 4b May

Your May game plan for Bowman County, North Dakota

May is a pivotal month for Bowman County, North Dakota gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 15
Avg. first frost September 24
Soil temp (4") 54°F
Watering Moderate
Pest pressure Low
Daylight 14.8 hrs
  1. Move hyssop into the garden

    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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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.

Bowman County, North Dakota is in USDA Zone 4b. The average last spring frost is May 15 and the first fall frost is September 24, giving you a growing season of approximately 132 days.

At an elevation of 753 feet, Bowman County receives approximately 25.8 inches of rainfall annually with predominantly loam soil. Summer highs average 81°F, so choose short-season varieties of Hyssop to ensure they mature before fall.

Bowman County, ND (Zone 4b) Short season
132 days
Last Spring Frost May 15
132 growing days
First Fall Frost September 24

Bowman County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 19 🍅 Harvest: Jul 28 – Sep 29
Recommended (50%) ✗ May not fit
Transplant: May 22 🍅 Harvest: Jul 31 – Oct 2
Safe Start (90%) ✗ May not fit
Transplant: Jun 9 🍅 Harvest: Aug 18 – Oct 20

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 Bowman County

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

Soil pH

Your soil pH (6.7–7.8) is within Hyssop's preferred range (6.0–8.0).

Soil Texture

The loam soil in Bowman County is excellent for Hyssop — good drainage, moisture retention, and nutrient holding capacity.

Drainage

Drainage is adequate for Hyssop.

Organic Matter

Organic matter is excellent (4.2%) — 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 132-day season

Sow every 8 weeks. Last sowing by Jun 26 to harvest before frost.

Plant Water Budget

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

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

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" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.5" 0" ❄️ Dormant
May 2.2" 3.2" 0" ✅ Rainfall sufficient
Jun 2.2" 1.9" 0.3" 💧 Light watering
Jul 2.2" 2.3" 0" ✅ Rainfall sufficient
Aug 2.2" 2.6" 0" ✅ Rainfall sufficient
Sep 2.2" 2.1" 0.1" 💧 Light watering
Oct 2.1" 0" ❄️ Dormant
Nov 2.1" 0" ❄️ Dormant
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Bowman County). 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 ~860 GDD — county provides 1,419 GDD Excellent fit

Hyssop Planting Timeline — Bowman County, ND

Hyssop Planting Calendar

Activity When Date Range
Transplant Outdoors May 22 May 22 – Jun 5
Harvest July 31 Jul 31 – Oct 2

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

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October Harvest
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: ideal

🗺️ USDA Zone

Zone 4b

📆 Growing Season

132 days in Bowman County

Growing Tips for Hyssop in Bowman County

Direct sow Hyssop outdoors after May 15 in Bowman County 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 Bowman County, ND?

Bowman County is in Zone 4b with an average last frost of May 15. Plan your Hyssop planting based on this frost date — see the calendar above for exact timing.

What planting zone is Bowman County, ND?

Bowman County, North Dakota is in USDA Hardiness Zone 4b. The average last spring frost is May 15 and first fall frost is September 24.

🌱

Your Bowman County Garden Planner — Free

A 24-page printable planner built for Bowman County (Zone 4b). 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 Bowman County, ND. 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.