Blog

When to Plant Brussels Sprouts in Rio Arriba County, NM

Rio Arriba County, New Mexico Zone 7a May

May in the garden — Rio Arriba County, New Mexico

Here's what deserves your attention in Rio Arriba County, New Mexico this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

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. Seed brussels sprouts outdoors

    Rake a smooth bed, make a shallow furrow, drop seeds at the spacing on the packet, water gently, walk away.

Coming up in June — start thinking about
  • Transplants going out: brussels sprouts

Instant PDF download. No spam, unsubscribe any time.

Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.

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 Brussels Sprouts to ensure they mature before fall. Sandy soil warms quickly in spring — great for early planting — but Brussels Sprouts will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Brussels Sprouts 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
Share this guide:

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 – Oct 31
Recommended (50%) ✗ May not fit
Start indoors: May 9 Transplant: Jun 13 🍅 Harvest: Sep 12 – Nov 7
Safe Start (90%) ✗ May not fit
Start indoors: May 20 Transplant: Jun 24 🍅 Harvest: Sep 23 – Nov 18

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 Brussels Sprouts's growing requirements.

Soil pH

Your soil pH (7.3–8.1) is more alkaline than Brussels Sprouts prefers (6.0–7.5). Add sulfur or peat moss to lower pH.

Soil Texture

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

Drainage

Drainage is adequate for Brussels Sprouts.

Organic Matter

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

How to Plant Brussels Sprouts

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
0.9″/week
Rainfall provides
0.8″/week
You supply
0.5″/week
Watering frequency 1-2 times/week
Season total 419 gal / 100 sq ft
Drought risk

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

Monthly Watering Guide for Brussels Sprouts

Brussels Sprouts needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.

Month Brussels Sprouts 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 3.9" 0.5" 3.4" 🚿 Regular watering
Jul 3.9" 2.6" 1.3" 💧 Light watering
Aug 3.9" 3.3" 0.6" 💧 Light watering
Sep 3.9" 2.6" 1.3" 💧 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.

Brussels Sprouts 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.

Brussels Sprouts needs ~1,430 GDD — county provides 1,248 GDD May not mature

Brussels Sprouts Planting Timeline — Rio Arriba County, NM

Brussels Sprouts 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 7
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
Share this guide:

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.9"/week · 1-2 times/week

📅 Days to Maturity

90–130 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

96 days in Rio Arriba County

Growing Tips for Brussels Sprouts in Rio Arriba County

Direct sow Brussels Sprouts 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 Brussels Sprouts 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 Brussels Sprouts (90.0-130.0 days to maturity). Start indoors and choose early-maturing varieties.

Common pests for Brussels Sprouts in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

Rio Arriba County receives only 17" of rain annually. Brussels Sprouts needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.

Companion Planting

Good Companions

Avoid Planting Near

  • Tomatoes
  • Strawberries

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Brussels Sprouts in Rio Arriba County, NM?

Rio Arriba County is in Zone 7a with an average last frost of June 13. Plan your Brussels Sprouts 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.

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 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.