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When to Plant Sunflower in Bernalillo County, NM

Sunflowers are tall, cheerful annuals grown for their edible seeds and as pollinator magnets. They come in sizes from 2-foot dwarfs to 12-foot giants.

Bernalillo County, New Mexico is in USDA Zone 7a. The average last spring frost is April 30 and the first fall frost is October 14, giving you a growing season of approximately 167 days.

At an elevation of 4,326 feet, Bernalillo County receives approximately 16.3 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 91ยฐF, providing good warmth for Sunflower during the growing season. Sandy soil warms quickly in spring โ€” great for early planting โ€” but Sunflower will need more frequent watering and organic matter to retain nutrients. With low rainfall, drip irrigation is essential for growing Sunflower successfully. Mulch heavily to conserve soil moisture.

Bernalillo County, NM (Zone 7a) Moderate season
167 days
Last Spring Frost April 30
167 growing days
First Fall Frost October 14

Bernalillo County Soil Profile

Soil Type

Sandy Loam

Soil pH

6.8-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (37 days to spare)
Start indoors: Feb 26 Transplant: Apr 30 🍅 Harvest: Jul 9 – Aug 27
Recommended (50%) ✓ Fits season (34 days to spare)
Start indoors: Mar 12 Transplant: May 14 🍅 Harvest: Jul 23 – Sep 10
Safe Start (90%) ✓ Fits season (32 days to spare)
Start indoors: Apr 11 Transplant: Jun 13 🍅 Harvest: Aug 22 – Oct 10

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 Bernalillo County

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

Soil pH

Your soil pH (6.8โ€“8.2) overlaps with Sunflower's range (6.0โ€“7.5), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Sunflower.

Organic Matter

Organic matter is low (0.7%). Add 2-3 inches of compost before planting Sunflower.

How to Plant Sunflower

1"
Planting Depth
18"
Between Plants
30"
Between Rows

Succession Planting Sunflower

2
successive plantings in your 167-day season

Sow every 8 weeks. Last sowing by Jul 06 to harvest before frost.

Plant Water Budget

Plant needs
0.5″/week
Rainfall provides
0.4″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 428 gal / 100 sq ft
Drought risk

Water stress score is 10/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Sunflower

Sunflower 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 Sunflower Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 0.8" 0" โ„๏ธ Dormant
Mar โ€” 0.8" 0" โ„๏ธ Dormant
Apr 2.2" 0.5" 1.7" ๐Ÿšฟ Regular watering
May 2.2" 0.3" 1.9" ๐Ÿšฟ Regular watering
Jun 2.2" 0.6" 1.6" ๐Ÿšฟ Regular watering
Jul 2.2" 3.1" 0" โœ… Rainfall sufficient
Aug 2.2" 3.2" 0" โœ… Rainfall sufficient
Sep 2.2" 2.3" 0" โœ… Rainfall sufficient
Oct 2.2" 1.4" 0.8" ๐Ÿ’ง Light watering
Nov โ€” 1" 0" โ„๏ธ Dormant
Dec โ€” 1.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Bernalillo County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Sunflower 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" โ€” every day above 50ยฐF 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.

Sunflower needs ~1,551 GDD — county provides 3,047 GDD Excellent fit

Sunflower Planting Timeline โ€” Bernalillo County, NM

Sunflower Planting Calendar

Activity When Date Range
Start Indoors March 12 Mar 12 โ€“ Mar 26
Transplant Outdoors May 14 May 14 โ€“ May 28
Direct Sow May 7 May 7 โ€“ May 28
Harvest July 23 Jul 23 โ€“ Sep 10

Plant 1" deep ยท 18" apart ยท Rows 30" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.5"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

70โ€“100 days

๐Ÿงช Soil pH

Needs 6โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

167 days in Bernalillo County

Growing Tips for Sunflower in Bernalillo County

Direct sow Sunflower outdoors after April 30 in Bernalillo County when soil has warmed and frost danger has passed.

Sandy soil in Bernalillo County dries quickly โ€” mulch Sunflower with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

Common pests for Sunflower in this region include aphids and slugs. Use row covers early in the season and inspect plants weekly.

Bernalillo County receives only 16" of rain annually. Sunflower needs consistent moisture โ€” install drip irrigation or water deeply 2-3 times per week.

General growing tips

Direct sow after last frost. Stake tall varieties in windy areas. Harvest seed heads when the back turns brown and seeds are plump. Dry heads upside down.

Companion Planting

Good Companions

Avoid Planting Near

  • Potatoes

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sunflower in Bernalillo County, NM?

Bernalillo County is in Zone 7a with an average last frost of April 30. Plan your Sunflower planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Bernalillo County, NM?

Bernalillo County, New Mexico is in USDA Hardiness Zone 7a. The average last spring frost is April 30 and first fall frost is October 14.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Bernalillo County gardeners in Zone 7a 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 Bernalillo County, NM. Local conditions may vary. Last updated: April 2026.