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When to Plant Onion in Holmes County, FL

Holmes County, Florida Zone 8b May

May in Holmes County, Florida — your action list

May is a pivotal month for Holmes County, Florida gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 15
Avg. first frost November 13
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 13.6 hrs
Coming up in June — start thinking about
  • First harvests: onion

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Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Holmes County, Florida is in USDA Zone 8b. The average last spring frost is March 15 and the first fall frost is November 13, giving you a growing season of approximately 243 days.

At an elevation of 164 feet, Holmes County receives approximately 57.8 inches of rainfall annually with predominantly sand soil. Summer highs average 93°F, providing good warmth for Onion during the growing season. Sandy soil warms quickly in spring — great for early planting — but Onion will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Onion root diseases.

Holmes County, FL (Zone 8b) Long season
243 days
Last Spring Frost March 15
243 growing days
First Fall Frost November 13
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Holmes County Soil Profile

Soil Type

Sand

Soil pH

5.2-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (104 days to spare)
Start indoors: Jan 30 Transplant: Mar 6 🍅 Harvest: Jun 5 – Jul 24
Recommended (50%) ✓ Fits season (103 days to spare)
Start indoors: Feb 8 Transplant: Mar 15 🍅 Harvest: Jun 14 – Aug 2
Safe Start (90%) ✓ Fits season (94 days to spare)
Start indoors: Mar 7 Transplant: Apr 11 🍅 Harvest: Jul 11 – Aug 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 Holmes County

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

Soil pH

Your soil pH (5.2–6.2) is more acidic than Onion prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

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

How to Plant Onion

1"
Planting Depth
6"
Between Plants
12"
Between Rows

Fall planting: Sow 10 weeks before your first frost date for a fall harvest.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Only during dry spells
Season total 3 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Onion

Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Onion Needs Rainfall You Supplement Action
Jan 3" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 4.3" 3.7" 0.6" 💧 Light watering
Apr 4.3" 2.9" 1.4" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 7.9" 0" ✅ Rainfall sufficient
Jul 4.3" 7.4" 0" ✅ Rainfall sufficient
Aug 4.3" 8.6" 0" ✅ Rainfall sufficient
Sep 4.3" 7.5" 0" ✅ Rainfall sufficient
Oct 4.3" 5.1" 0" ✅ Rainfall sufficient
Nov 4.3" 2.1" 2.2" 🚿 Regular watering
Dec 2.3" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Holmes County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Onion 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.

Onion needs ~2,074 GDD — county provides 4,799 GDD Excellent fit

Onion Planting Timeline — Holmes County, FL

Onion Planting Calendar

Activity When Date Range
Start Indoors February 8 Feb 8 – Feb 22
Transplant Outdoors March 15 Mar 15 – Mar 29
Direct Sow March 1 Mar 1 – Mar 22
Harvest June 14 Jun 14 – Aug 2
Fall Sowing September 4 Sep 4 – Sep 18

Plant 1" deep · 6" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Transplant Outdoors Direct Sow
April
May
June Harvest
July Harvest
August Harvest
September Fall Sowing
October
November
December
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Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

90–120 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 8b

📆 Growing Season

243 days in Holmes County

Growing Tips for Onion in Holmes County

Direct sow Onion outdoors after March 15 in Holmes County when soil has warmed and frost danger has passed.

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

Common pests for Onion in this region include onion maggots and thrips. Use row covers early in the season and inspect plants weekly.

General growing tips

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Holmes County, FL?

Holmes County is in Zone 8b with an average last frost of March 15. Plan your Onion planting based on this frost date — see the calendar above for exact timing.

What planting zone is Holmes County, FL?

Holmes County, Florida is in USDA Hardiness Zone 8b. The average last spring frost is March 15 and first fall frost is November 13.

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Your Holmes County Garden Planner — Free

A 24-page printable planner built for Holmes County (Zone 8b). 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 Holmes County, FL. 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.