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When to plant Sweet Alyssum in Leon County County,

In Leon County County, plant Sweet Alyssum in spring between January 14 and February 4, once soil temps hold above 50°F. Leon County County's last frost averages March 11, so aim for a steady week of warm soil before planting. For a fall crop, sow between September 12 and September 26 — roughly 60 days before the first frost on November 21.

When to Plant Sweet Alyssum in Leon County, FL

Leon County, Florida Zone 9a June

This month in Leon County, Florida

If you only do a handful of things in the garden this June, make it these. They're sequenced around your zone's frost timing.

Avg. last frost March 11
Avg. first frost November 21
Soil temp (4") 82°F
Watering Low
Pest pressure High
Daylight 14 hrs
  1. It's harvest week for sweet alyssum

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

Looking ahead to July
  • First harvests: sweet alyssum

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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.

Leon County, Florida is in USDA Zone 9a. The average last spring frost is March 11 and the first fall frost is November 21, giving you a growing season of approximately 255 days.

At an elevation of 250 feet, Leon County receives approximately 53.9 inches of rainfall annually with predominantly sand soil. Summer highs average 95°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
Leon County, FL (Zone 9a) Long season
255 days
Last Spring Frost March 11
255 growing days
First Fall Frost November 21
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Leon County Soil Profile

Soil Type

Sand

Soil pH

4.8-5.7

Drainage

Well Drained

Sweet Alyssum Planting Risk Windows

Early Start (70% safe) ✓ Fits season (141 days to spare)
Transplant: Feb 3 🌸 Bloom: Mar 10 – Jun 23
Recommended (50%) ✓ Fits season (143 days to spare)
Transplant: Feb 11 🌸 Bloom: Mar 18 – Jul 1
Safe Start (90%) ✓ Fits season (140 days to spare)
Transplant: Mar 7 🌸 Bloom: Apr 11 – Jul 25

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 Leon County

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

Soil pH

Your soil pH (4.8–5.7) is more acidic than Sweet Alyssum prefers (6.0–7.5). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Sweet Alyssum.

Organic Matter

Organic matter is low (1.3%). 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

6
successive plantings in your 255-day season

Sow every 5.1 weeks. Last sowing by Sep 22 to harvest before frost.

For a dedicated fall crop, sow by Sep 12.

Sweet Alyssum Water Budget

Plant needs
0.5″/week
Rainfall provides
0.9″/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 2.2" 0" ❄️ Dormant
Feb 3.3" 0" ❄️ Dormant
Mar 2.2" 3" 0" ✅ Rainfall sufficient
Apr 2.2" 2.4" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 7.2" 0" ✅ Rainfall sufficient
Jul 2.2" 7.6" 0" ✅ Rainfall sufficient
Aug 2.2" 7.5" 0" ✅ Rainfall sufficient
Sep 2.2" 6.9" 0" ✅ Rainfall sufficient
Oct 2.2" 5.2" 0" ✅ Rainfall sufficient
Nov 2.2" 2.1" 0.1" 💧 Light watering
Dec 2.6" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Leon 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 ~1,116 GDD — county provides 5,418 GDD Excellent fit

Sweet Alyssum Planting Timeline — Leon County, FL

Sweet Alyssum Planting Calendar

Activity When Date Range
Transplant Outdoors February 11 Feb 11 – Feb 25
Direct Sow January 14 Jan 14 – Feb 4
Bloom March 18 Mar 18 – Jul 1
Fall Sowing September 12 Sep 12 – Sep 26

· 6" apart · Rows 8" apart

Month-by-Month Timeline

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

255 days in Leon County

Growing Tips for Sweet Alyssum in Leon County

Direct sow Sweet Alyssum outdoors after March 11 in Leon County when soil has warmed and frost danger has passed.

Sandy soil in Leon 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.

Your generous 255.0-day season in Leon 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 Leon County, FL?

Leon County is in Zone 9a with an average last frost of March 11. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.

What planting zone is Leon County, FL?

Leon County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 11 and first fall frost is November 21.

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

In Leon County County, , plant Sweet Alyssum after the last frost (around March 11) and before the first frost (around November 21). Best results when soil holds above 50°F.

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

Leon 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 Leon County County's climate?

Yes — Sweet Alyssum grows well in Leon County County's temperate climate. Leon County County averages a 255-day frost-free season, with last frost around March 11 and first frost around November 21.

🌱

Your Leon County Garden Planner — Free

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

Sources & credits

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