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When to plant Sweet Alyssum in Nassau County County,

Nassau County County's climate puts the Sweet Alyssum spring window between December 20 and January 10. aim for a steady week of warm soil before planting. A second sowing from September 22 to October 6 extends the harvest into fall.

When to Plant Sweet Alyssum in Nassau County, FL

Nassau County, Florida Zone 9a June

June in Nassau County, Florida — your action list

Welcome to June in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 14
Avg. first frost December 1
Soil temp (4") 85°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. Collect sweet alyssum at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

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Sweet Alyssum (Lobularia maritima) is a low-growing cool-season annual prized for its honey-scented clusters of tiny white, pink, or purple flowers. A workhorse border plant, it tolerates light frost, self-seeds readily, and attracts beneficial insects throughout its bloom season. In warm climates it often re-blooms in fall after summer heat fades.

Nassau County, Florida is in USDA Zone 9a. The average last spring frost is February 14 and the first fall frost is December 1, giving you a growing season of approximately 290 days.

At an elevation of 408 feet, Nassau County receives approximately 57.9 inches of rainfall annually with predominantly sand soil. Summer highs average 101°F, so Sweet Alyssum may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Sweet Alyssum will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Sweet Alyssum root diseases.

Annual Blooms in Spring Pollinator-friendly Deer-resistant Fragrant
Nassau County, FL (Zone 9a) Year-round
290 days
Last Spring Frost February 14
290 growing days
First Fall Frost December 1

Nassau County Soil Profile

Soil Type

Sand

Soil pH

5.2-5.8

Drainage

Well Drained

Sweet Alyssum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (176 days to spare)
Transplant: Jan 10 🌸 Bloom: Feb 14 – May 30
Recommended (50%) ✓ Fits season (178 days to spare)
Transplant: Jan 17 🌸 Bloom: Feb 21 – Jun 6
Safe Start (90%) ✓ Fits season (160 days to spare)
Transplant: Feb 23 🌸 Bloom: Mar 30 – Jul 13

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 Nassau County

How your county's soil matches Sweet Alyssum's growing requirements.

Soil pH

Your soil pH (5.2–5.8) is more acidic than Sweet Alyssum prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Organic Matter

Organic matter is low (1.4%). Add 2-3 inches of compost before planting Sweet Alyssum.

How to Plant Sweet Alyssum

6"
Between Plants
8"
Between Rows

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

Succession Planting Sweet Alyssum

7
successive plantings in your 290-day season

Sow every 5.1 weeks. Last sowing by Oct 02 to harvest before frost.

For a dedicated fall crop, sow by Sep 22.

Sweet Alyssum Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Sweet Alyssum

Sweet Alyssum 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 Sweet Alyssum Needs Rainfall You Supplement Action
Jan 2.8" 0" ❄️ Dormant
Feb 2.2" 3.2" 0" ✅ Rainfall sufficient
Mar 2.2" 3.7" 0" ✅ Rainfall sufficient
Apr 2.2" 2.9" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 6.6" 0" ✅ Rainfall sufficient
Jul 2.2" 7.9" 0" ✅ Rainfall sufficient
Aug 2.2" 8.7" 0" ✅ Rainfall sufficient
Sep 2.2" 7.9" 0" ✅ Rainfall sufficient
Oct 2.2" 5.3" 0" ✅ Rainfall sufficient
Nov 2.2" 2.2" 0" ✅ Rainfall sufficient
Dec 2.2" 2.5" 0" ✅ Rainfall sufficient

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

Sweet Alyssum 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.

Sweet Alyssum needs ~1,352 GDD — county provides 7,493 GDD Excellent fit

Sweet Alyssum Planting Timeline — Nassau County, FL

Sweet Alyssum Planting Calendar

Activity When Date Range
Transplant Outdoors January 17 Jan 17 – Jan 31
Direct Sow December 20 Dec 20 – Jan 10
Bloom February 21 Feb 21 – Jun 6
Fall Sowing September 22 Sep 22 – Oct 6

· 6" apart · Rows 8" apart

Month-by-Month Timeline

MonthActivities
January Transplant Outdoors Direct Sow
February Bloom
March Bloom
April Bloom
May Bloom
June Bloom
July
August
September Fall Sowing
October Fall Sowing
November
December Direct Sow

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

45–60 days

🧪 Soil pH

Needs 6–7.5 · Your soil: too_acidic

🗺️ USDA Zone

Zone 9a

📆 Growing Season

290 days in Nassau County

Growing Tips for Sweet Alyssum in Nassau County

Direct sow Sweet Alyssum outdoors after February 14 in Nassau County when soil has warmed and frost danger has passed.

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

With summer highs reaching 101°F in Nassau County, provide afternoon shade for Sweet Alyssum and water deeply in the morning.

Your generous 291.0-day season in Nassau County allows multiple plantings of Sweet Alyssum. Sow every 22.0 days for continuous harvest.

Common pests for Sweet Alyssum in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.

General growing tips

Surface-sow seeds — they need light to germinate. Direct-sow as soon as soil can be worked in spring; in zones 7+ also sow in fall. Thin to 6 inches apart. Shear back hard in midsummer when heat causes dormancy — plants recover and re-bloom when cool weather returns. Self-seeds prolifically; allow a few plants to set seed for a perpetual colony.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Sweet Alyssum in Nassau County, FL?

Nassau County is in Zone 9a with an average last frost of February 14. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Nassau County, FL?

Nassau County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is February 14 and first fall frost is December 1.

When should I plant Sweet Alyssum in Nassau County County, ?

In Nassau County County, , plant Sweet Alyssum after the last frost (around February 14) and before the first frost (around December 1). Best results when soil holds above 50°F.

What growing zone is Nassau County County, for Sweet Alyssum?

Nassau County County sits in USDA Zone 9a. Sweet Alyssum grows reliably in zones 3a through 11b, so it's a good fit here.

Can Sweet Alyssum grow in Nassau County County's climate?

Yes — Sweet Alyssum grows well in Nassau County County's temperate climate. Nassau County County averages a 291-day frost-free season, with last frost around February 14 and first frost around December 1.

🌱

Your Nassau County Garden Planner — Free

A 22-page printable planner built for Nassau 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 Nassau County, FL. Local conditions may vary. Last updated: June 2026.

Sources & credits

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