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When to Plant Horehound in Oliver County, ND

Oliver County, North Dakota Zone 4a April

Your April game plan for Oliver County, North Dakota

April rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Oliver County, North Dakota.

Avg. last frost May 14
Avg. first frost September 26
Soil temp (4") 41°F
Watering High
Pest pressure Low
Daylight 13.4 hrs
A few tasks this April that'll pay off in May
  • Transplants going out: horehound

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Horehound is a woolly, drought-tolerant perennial herb traditionally used for cough remedies and candy. It has a distinctive bitter, menthol-like flavor.

Oliver County, North Dakota is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 721 feet, Oliver County receives approximately 21.1 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Horehound to ensure they mature before fall.

Oliver County, ND (Zone 4a) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26
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Oliver County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 17 🍅 Harvest: Aug 2 – Sep 27
Recommended (50%) ✗ May not fit
Transplant: May 21 🍅 Harvest: Aug 6 – Oct 1
Safe Start (90%) ✗ May not fit
Transplant: Jun 5 🍅 Harvest: Aug 21 – Oct 16

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 Oliver County

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

Soil pH

Your soil pH (6.5–7.4) is within Horehound's preferred range (6.0–8.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.0%) — Horehound will thrive.

How to Plant Horehound

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

Succession Planting Horehound

2
successive plantings in your 135-day season

Sow every 8.6 weeks. Last sowing by Jun 28 to harvest before frost.

Plant Water Budget

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

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

Monthly Watering Guide for Horehound

Horehound 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 Horehound Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.3" 0" ❄️ Dormant
May 2.2" 2.4" 0" ✅ Rainfall sufficient
Jun 2.2" 1.7" 0.5" 💧 Light watering
Jul 2.2" 1.9" 0.3" 💧 Light watering
Aug 2.2" 2.5" 0" ✅ Rainfall sufficient
Sep 2.2" 1.7" 0.5" 💧 Light watering
Oct 1.7" 0" ❄️ Dormant
Nov 1.3" 0" ❄️ Dormant
Dec 1.4" 0" ❄️ Dormant

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

Horehound 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.

Horehound needs ~825 GDD — county provides 1,350 GDD Excellent fit

Horehound Planting Timeline — Oliver County, ND

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 – Jun 4
Harvest August 6 Aug 6 – Oct 1

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
August Harvest
September Harvest
October Harvest
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

75–90 days

🧪 Soil pH

Needs 6–8 · Your soil: ideal

🗺️ USDA Zone

Zone 4a

📆 Growing Season

135 days in Oliver County

Growing Tips for Horehound in Oliver County

Direct sow Horehound outdoors after May 14 in Oliver County when soil has warmed and frost danger has passed.

Oliver County receives only 21" of rain annually. Horehound needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow or start from divisions. Thrives in poor, dry soil. Harvest stems just before flowering. Deadhead to prevent aggressive self-seeding. Very drought-tolerant once established.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Horehound in Oliver County, ND?

Oliver County is in Zone 4a with an average last frost of May 14. Plan your Horehound planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oliver County, ND?

Oliver County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 26.

🌱

Your Oliver County Garden Planner — Free

A 24-page printable planner built for Oliver County (Zone 4a). 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 Oliver County, ND. Local conditions may vary. Last updated: April 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.