Blog

When to Plant Asparagus in Adair County, OK

Asparagus is a long-lived perennial vegetable that produces tender spears each spring for 15-20 years once established. It requires patience but rewards with reliable harvests.

Adair County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 27, giving you a growing season of approximately 203 days.

At an elevation of 486 feet, Adair County receives approximately 33.9 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Asparagus during the growing season.

Adair County, OK (Zone 7a) Long season
203 days
Last Spring Frost April 7
203 growing days
First Fall Frost October 27

Adair County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 11
Recommended (50%) ✓ Fits season
Transplant: Apr 21
Safe Start (90%) ✓ Fits season
Transplant: May 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 Adair County

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

Soil pH

Your soil pH (6.7โ€“7.1) is within Asparagus's preferred range (6.5โ€“7.5).

Soil Texture

The loam soil in Adair County is excellent for Asparagus โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) โ€” Asparagus will thrive.

How to Plant Asparagus

1"
Planting Depth
30"
Between Plants
42"
Between Rows

Plant Water Budget

Plant needs
0.8″/week
Rainfall provides
0.7″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 178 gal / 100 sq ft

Monthly Watering Guide for Asparagus

Asparagus 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 Asparagus Needs Rainfall You Supplement Action
Jan โ€” 1" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 2.4" 0" โ„๏ธ Dormant
Apr 3.5" 4.2" 0" โœ… Rainfall sufficient
May 3.5" 4.5" 0" โœ… Rainfall sufficient
Jun 3.5" 5.5" 0" โœ… Rainfall sufficient
Jul 3.5" 4.1" 0" โœ… Rainfall sufficient
Aug 3.5" 3.6" 0" โœ… Rainfall sufficient
Sep 3.5" 3.1" 0.4" ๐Ÿ’ง Light watering
Oct 3.5" 2.4" 1.1" ๐Ÿ’ง Light watering
Nov โ€” 1.2" 0" โ„๏ธ Dormant
Dec โ€” 0.8" 0" โ„๏ธ Dormant

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

Asparagus 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.

Asparagus needs ~18,022 GDD — county provides 4,009 GDD May not mature

Asparagus Planting Timeline โ€” Adair County, OK

Asparagus Planting Calendar

Activity When Date Range
Transplant Outdoors April 21 Apr 21 โ€“ May 5

Plant 1" deep ยท 30" apart ยท Rows 42" apart

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.8"/week ยท Only during dry spells

๐Ÿ“… Days to Maturity

730โ€“1095 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: ideal

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

203 days in Adair County

Growing Tips for Asparagus in Adair County

Direct sow Asparagus outdoors after April 07 in Adair County when soil has warmed and frost danger has passed.

Your 203.0-day growing season in Adair County is tight for Asparagus (730.0-1095.0 days to maturity). Start indoors and choose early-maturing varieties.

General growing tips

Plant crowns in deep trenches with compost. Do not harvest spears for the first two years to allow root establishment. Mulch heavily to suppress weeds and retain moisture.

Companion Planting

Good Companions

Avoid Planting Near

  • Garlic
  • Onion

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Asparagus in Adair County, OK?

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

What planting zone is Adair County, OK?

Adair County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 27.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Adair County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Adair County, OK. Local conditions may vary. Last updated: April 2026.