When to Plant Sweet Alyssum in Saskatoon, SK
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.
Saskatoon, Saskatchewan is in USDA Zone 4a. The average last spring frost is May 18 and the first fall frost is October 5, giving you a growing season of approximately 140 days.
At an elevation of 1,581 feet, Saskatoon receives approximately 14 inches of rainfall annually with predominantly dark brown chernozem soil. Summer highs average 74°F, so choose short-season varieties of Sweet Alyssum to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Sweet Alyssum successfully. Mulch heavily to conserve soil moisture.
Saskatoon Soil Profile
Soil Type
Dark Brown Chernozem
Soil pH
6.0-7.0
Drainage
Well Drained
Sweet Alyssum Planting Timeline — Saskatoon, SK
Sweet Alyssum Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 23 | Mar 23 – Apr 6 |
| Transplant Outdoors | May 18 | May 18 – Jun 1 |
| Direct Sow | May 11 | May 11 – Jun 1 |
| Bloom | June 29 | Jun 29 – Aug 31 |
· 6" apart · Rows 8" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | Start Indoors |
| April | Start Indoors |
| May | Transplant Outdoors Direct Sow |
| June | Transplant Outdoors Direct Sow Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
Low — drought tolerant
📅 Days to Maturity
45–60 days
🧪 Soil pH
Needs 6–7.5 · Your soil: N/A
🗺️ USDA Zone
Zone 4a
📆 Growing Season
140 days in Saskatoon
Growing Tips for Saskatoon
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 Saskatoon, SK?
Saskatoon is in Zone 4a with an average last frost of May 18. Plan your Sweet Alyssum planting based on this frost date — see the calendar above for exact timing.
What planting zone is Saskatoon, SK?
Saskatoon, Saskatchewan is in USDA Hardiness Zone 4a. The average last spring frost is May 18 and first fall frost is October 5.
Your Saskatoon Garden Planner — Free
A 22-page printable planner built for Saskatoon (Zone 4a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.