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When to Plant Leeks in Rio Arriba County, NM

Rio Arriba County, New Mexico Zone 7a May

Rio Arriba County, New Mexico gardeners: here's your May plan

Your garden in Rio Arriba County, New Mexico is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost June 13
Avg. first frost September 17
Soil temp (4") 44°F
Watering Critical
Pest pressure Low
Daylight 13.9 hrs
  1. Scatter leeks into prepared beds

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

Get ahead of June
  • Transplants going out: leeks

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Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

Rio Arriba County, New Mexico is in USDA Zone 7a. 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 84°F, so choose short-season varieties of Leeks to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Leeks will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Leeks successfully. Mulch heavily to conserve soil moisture.

Rio Arriba County, NM (Zone 7a) 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
Start indoors: May 2 Transplant: Jun 6 🍅 Harvest: Sep 5 – Nov 21
Recommended (50%) ✗ May not fit
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Sep 12 – Nov 28
Safe Start (90%) ✗ May not fit
Start indoors: May 20 Transplant: Jun 24 🍅 Harvest: Sep 23 – Dec 9

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 Rio Arriba County

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

Soil pH

Your soil pH (7.3–8.1) is more alkaline than Leeks prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Sandy soil in Rio Arriba County warms quickly in spring but drains fast. Leeks will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Leeks.

Organic Matter

Organic matter is low (0.8%). Add 2-3 inches of compost before planting Leeks.

How to Plant Leeks

1"
Planting Depth
15"
Between Plants
24"
Between Rows

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

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 286 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Leeks

Leeks needs approximately 0.8 inches of water per week (3.5" per month). Here's how your county's rainfall compares month by month.

Month Leeks Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 0.9" 0" ❄️ Dormant
Apr 0.6" 0" ❄️ Dormant
May 0.5" 0" ❄️ Dormant
Jun 3.5" 0.5" 3" 🚿 Regular watering
Jul 3.5" 2.6" 0.9" 💧 Light watering
Aug 3.5" 3.3" 0.2" 💧 Light watering
Sep 3.5" 2.6" 0.9" 💧 Light watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

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

Leeks 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.

Leeks needs ~1,560 GDD — county provides 1,248 GDD May not mature

Leeks Planting Timeline — Rio Arriba County, NM

Leeks Planting Calendar

Activity When Date Range
Start Indoors May 9 May 9 – May 23
Transplant Outdoors June 13 Jun 13 – Jun 27
Direct Sow May 30 May 30 – Jun 20
Harvest September 12 Sep 12 – Nov 28
Fall Sowing July 9 Jul 9 – Jul 23

Plant 1" deep · 15" apart · Rows 24" apart

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · 1-2 times/week

📅 Days to Maturity

90–150 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

96 days in Rio Arriba County

Growing Tips for Leeks in Rio Arriba County

Direct sow Leeks outdoors after June 13 in Rio Arriba County when soil has warmed and frost danger has passed.

Sandy soil in Rio Arriba County dries quickly — mulch Leeks with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Your 96.0-day growing season in Rio Arriba County is tight for Leeks (90.0-150.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Leeks in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

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

Rio Arriba County is in Zone 7a with an average last frost of June 13. Plan your Leeks planting based on this frost date — 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 7a. The average last spring frost is June 13 and first fall frost is September 17.

🌱

Your Rio Arriba County Garden Planner — Free

A 24-page printable planner built for Rio Arriba County (Zone 7a). 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 Rio Arriba County, NM. 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.