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When to plant Asparagus in Union County, FL

Union County's 271-day season only supports one Asparagus planting per year. Sow between March 15 and March 29 for the best chance at full maturity before November 27.

When to Plant Asparagus in Union County, FL

Asparagus
Union County, Florida Zone 9a August

This month in Union County, Florida

A quick August briefing for Union County, Florida gardeners — what's urgent, what's next, and what can wait.

Avg. last frost March 1
Avg. first frost November 27
Soil temp (4") 97°F
Watering Low
Pest pressure High
Daylight 13.1 hrs

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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.

Union County, Florida is in USDA Zone 9a. The average last spring frost is March 1 and the first fall frost is November 27, giving you a growing season of approximately 271 days.

At an elevation of 360 feet, Union County receives approximately 60.6 inches of rainfall annually with predominantly sand soil. Summer highs average 96°F, so Asparagus may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Asparagus will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Asparagus root diseases.

Union County, FL (Zone 9a) Year-round
271 days
Last Spring Frost March 1
271 growing days
First Fall Frost November 27

Union County Soil Profile

Soil Type

Sand

Soil pH

5.2-6

Drainage

Well Drained

Asparagus Planting Risk Windows

Early Start (70% safe) ✓ Fits season
Transplant: Feb 28
Recommended (50%) ✓ Fits season
Transplant: Mar 15
Safe Start (90%) ✓ Fits season
Transplant: Apr 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 Union County

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

Soil pH

Your soil pH (5.2–6.0) is more acidic than Asparagus prefers (6.5–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Asparagus.

Organic Matter

Organic matter is low (1.3%). Add 2-3 inches of compost before planting Asparagus.

How to Plant Asparagus

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

Asparagus Water Budget

Plant needs
0.8″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 243 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 3.1" 0" ❄️ Dormant
Feb 2.7" 0" ❄️ Dormant
Mar 3.5" 3.5" 0" ✅ Rainfall sufficient
Apr 3.5" 2.8" 0.7" 💧 Light watering
May 3.5" 4.4" 0" ✅ Rainfall sufficient
Jun 3.5" 8.1" 0" ✅ Rainfall sufficient
Jul 3.5" 10" 0" ✅ Rainfall sufficient
Aug 3.5" 9" 0" ✅ Rainfall sufficient
Sep 3.5" 7.2" 0" ✅ Rainfall sufficient
Oct 3.5" 4.5" 0" ✅ Rainfall sufficient
Nov 3.5" 2.7" 0.8" 💧 Light watering
Dec 2.5" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Union County). Supplement amounts are based on average rainfall — 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" — 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.

Asparagus needs ~20,075 GDD — county provides 5,962 GDD May not mature

Asparagus Planting Timeline — Union County, FL

Asparagus Planting Calendar

Activity When Date Range
Transplant Outdoors March 15 Mar 15 – Mar 29

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.8"/week · Only during dry spells

📅 Days to Maturity

730–1095 days

🧪 Soil pH

Needs 6.5–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

271 days in Union County

Growing Tips for Asparagus in Union County

Direct sow Asparagus outdoors after March 01 in Union County when soil has warmed and frost danger has passed.

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

With summer highs reaching 96°F in Union County, provide afternoon shade for Asparagus and water deeply in the morning.

Your 271.0-day growing season in Union 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 Union County, FL?

Union County is in Zone 9a with an average last frost of March 1. Plan your Asparagus planting based on this frost date — see the calendar above for exact timing.

What planting zone is Union County, FL?

Union County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 1 and first fall frost is November 27.

When should I plant Asparagus in Union County, FL?

In Union County, FL, plant Asparagus after the last frost (around March 1) and before the first frost (around November 27). Best results when soil holds above 50°F.

What growing zone is Union County, FL for Asparagus?

Union County sits in USDA Zone 9a. Asparagus grows reliably in zones 3a through 10b, so it's a good fit here.

Can Asparagus grow in Union County's climate?

Yes — Asparagus grows well in Union County's temperate climate. Union County averages a 271-day frost-free season, with last frost around March 1 and first frost around November 27.

🌱

Your Union County Garden Planner — Free

A 22-page printable planner built for Union County (Zone 9a). 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 Union County, FL. Local conditions may vary. Last updated: August 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.