When to plant Sweet Alyssum in Clinton County County,
The best window to plant Sweet Alyssum in Clinton County County, is April 9–April 30, when soil warms to 50°F. Last frost typically hits April 30; first frost October 13.
When to Plant Sweet Alyssum in Clinton County, MI
Your June planting checklist for Clinton County, Michigan
Welcome to June in Zone 6a. These are the moves that will have the biggest impact on your growing season.
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Time to start sweet alyssum inside
Bottom-water once the first true leaves appear — it keeps stems dry and knocks back damping-off.
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Pick sweet alyssum
The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.
A few tasks this June that'll pay off in July
- First harvests: sweet alyssum
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.
Clinton County, Michigan is in USDA Zone 6a. The average last spring frost is April 30 and the first fall frost is October 13, giving you a growing season of approximately 166 days.
At an elevation of 519 feet, Clinton County receives approximately 34.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Sweet Alyssum to ensure they mature before fall.
Clinton County Soil Profile
Soil Type
Silt Loam
Soil pH
5.9-6.7
Drainage
Well Drained
Sweet Alyssum Planting Risk Windows
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 Clinton County
How your county's soil matches Sweet Alyssum's growing requirements.
Soil pH
Your soil pH (5.9–6.7) overlaps with Sweet Alyssum's range (6.0–7.5), though not a perfect match.
Soil Texture
The silt loam soil in Clinton County is excellent for Sweet Alyssum — good drainage, moisture retention, and nutrient holding capacity.
Drainage
Drainage is adequate for Sweet Alyssum.
Organic Matter
Organic matter is excellent (4.8%) — Sweet Alyssum will thrive.
How to Plant Sweet Alyssum
Succession Planting Sweet Alyssum
Sow every 5.1 weeks. Last sowing by Aug 14 to harvest before frost.
Sweet Alyssum Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
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 | — | 1.4" | 0" | ❄️ Dormant |
| Feb | — | 1.7" | 0" | ❄️ Dormant |
| Mar | — | 2.4" | 0" | ❄️ Dormant |
| Apr | 2.2" | 2.9" | 0" | ✅ Rainfall sufficient |
| May | 2.2" | 3.8" | 0" | ✅ Rainfall sufficient |
| Jun | 2.2" | 4.1" | 0" | ✅ Rainfall sufficient |
| Jul | 2.2" | 3.7" | 0" | ✅ Rainfall sufficient |
| Aug | 2.2" | 3.9" | 0" | ✅ Rainfall sufficient |
| Sep | 2.2" | 3" | 0" | ✅ Rainfall sufficient |
| Oct | 2.2" | 2.7" | 0" | ✅ Rainfall sufficient |
| Nov | — | 2.5" | 0" | ❄️ Dormant |
| Dec | — | 2" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in Clinton 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 Planting Timeline — Clinton County, MI
Sweet Alyssum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 12 | Mar 12 – Mar 26 |
| Transplant Outdoors | April 30 | Apr 30 – May 14 |
| Direct Sow | April 9 | Apr 9 – Apr 30 |
| Bloom | June 11 | Jun 11 – Aug 20 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Transplant Outdoors Direct Sow |
| May | Transplant Outdoors |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
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: acceptable
🗺️ USDA Zone
Zone 6a
📆 Growing Season
166 days in Clinton County
Growing Tips for Sweet Alyssum in Clinton County
Direct sow Sweet Alyssum outdoors after April 30 in Clinton County when soil has warmed and frost danger has passed.
Your generous 166.0-day season in Clinton 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 →
Sweet Alyssum in Other Locations
Frequently Asked Questions
When should I plant Sweet Alyssum in Clinton County, MI?
Clinton County is in Zone 6a with an average last frost of April 30. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Clinton County, MI?
Clinton County, Michigan is in USDA Hardiness Zone 6a. The average last spring frost is April 30 and first fall frost is October 13.
When should I plant Sweet Alyssum in Clinton County County, ?
In Clinton County County, , plant Sweet Alyssum after the last frost (around April 30) and before the first frost (around October 13). Best results when soil holds above 50°F.
What growing zone is Clinton County County, for Sweet Alyssum?
Clinton County County sits in USDA Zone 6a. Sweet Alyssum grows reliably in zones 3a through 11b, so it's a good fit here.
Can Sweet Alyssum grow in Clinton County County's climate?
Yes — Sweet Alyssum grows well in Clinton County County's temperate climate. Clinton County County averages a 166-day frost-free season, with last frost around April 30 and first frost around October 13.
Your Clinton County Garden Planner — Free
A 22-page printable planner built for Clinton County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.