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When to Plant Horehound in Rio Arriba County, NM

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

Rio Arriba County, New Mexico is in USDA Zone 5b. The average last spring frost is June 13 and the first fall frost is September 17, giving you a growing season of approximately 96 days.

At an elevation of 5,979 feet, Rio Arriba County receives approximately 17.4 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Horehound to ensure they mature before fall. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Horehound will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Horehound successfully. Mulch heavily to conserve soil moisture.

Rio Arriba County, NM (Zone 5b) Very short season
96 days
Last Spring Frost June 13
96 growing days
First Fall Frost September 17

Rio Arriba County Soil Profile

Soil Type

Sandy Loam

Soil pH

7.3-8.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: Jun 13 🍅 Harvest: Aug 29 – Oct 24
Recommended (50%) ✗ May not fit
Transplant: Jun 20 🍅 Harvest: Sep 5 – Oct 31
Safe Start (90%) ✗ May not fit
Transplant: Jul 1 🍅 Harvest: Sep 16 – Nov 11

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.

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 10/10 โ€” consider drought-tolerant varieties and mulching

Horehound needs ~1,072 GDD — county provides 1,248 GDD Good fit

Horehound Planting Timeline โ€” Rio Arriba County, NM

Horehound Planting Calendar

Activity When Date Range
Transplant Outdoors June 20 Jun 20 โ€“ Jul 4
Harvest September 5 Sep 5 โ€“ Oct 31

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Low โ€” drought tolerant

Days to Maturity

75โ€“90 days

Soil pH

6 โ€“ 8

USDA Zone

Zone 5b

Growing Season

96 days

Growing Tips for Rio Arriba County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Horehound in Rio Arriba County, NM?

Rio Arriba County is in Zone 5b with an average last frost of June 13. Plan your Horehound planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Rio Arriba County, NM?

Rio Arriba County, New Mexico is in USDA Hardiness Zone 5b. The average last spring frost is June 13 and first fall frost is September 17.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Rio Arriba County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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 Rio Arriba County, NM. Local conditions may vary. Last updated: April 2026.