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When to Plant Asparagus in Stephens 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.

Stephens County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 6 and the first fall frost is November 1, giving you a growing season of approximately 209 days.

At an elevation of 979 feet, Stephens County receives approximately 26.1 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Asparagus during the growing season.

Stephens County, OK (Zone 7b) Long season
209 days
Last Spring Frost April 6
209 growing days
First Fall Frost November 1

Stephens County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Apr 11
Recommended (50%) ✓ Fits season
Transplant: Apr 20
Safe Start (90%) ✓ Fits season
Transplant: Apr 29

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 Stephens County

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

Soil pH

Your soil pH (6.3โ€“7.6) overlaps with Asparagus's range (6.5โ€“7.5), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.3%) 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
0.5″/week
You supply
0.3″/week
Watering frequency 1-2 times/week
Season total 615 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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€” 0.6" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.6" 0" โ„๏ธ Dormant
Apr 3.5" 2.7" 0.8" ๐Ÿ’ง Light watering
May 3.5" 3.9" 0" โœ… Rainfall sufficient
Jun 3.5" 4.3" 0" โœ… Rainfall sufficient
Jul 3.5" 3" 0.5" ๐Ÿ’ง Light watering
Aug 3.5" 3.5" 0" โœ… Rainfall sufficient
Sep 3.5" 2.4" 1.1" ๐Ÿ’ง Light watering
Oct 3.5" 1.9" 1.6" ๐Ÿ’ง Light watering
Nov 3.5" 0.8" 2.7" ๐Ÿšฟ Regular watering
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Stephens 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 ~15,969 GDD — county provides 3,657 GDD May not mature

Asparagus Planting Timeline โ€” Stephens County, OK

Asparagus Planting Calendar

Activity When Date Range
Transplant Outdoors April 20 Apr 20 โ€“ May 4

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 1-2 times/week

๐Ÿ“… Days to Maturity

730โ€“1095 days

๐Ÿงช Soil pH

Needs 6.5โ€“7.5 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

209 days in Stephens County

Growing Tips for Asparagus in Stephens County

Direct sow Asparagus outdoors after April 06 in Stephens County when soil has warmed and frost danger has passed.

Your 209.0-day growing season in Stephens 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 Stephens County, OK?

Stephens County is in Zone 7b with an average last frost of April 6. Plan your Asparagus planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Stephens County, OK?

Stephens County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 6 and first fall frost is November 1.

๐ŸŒฑ

Plan Your Garden with Confidence

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