Climate-based cabbage planting guide for Slave Lake, Alberta

When to Plant Cabbage in Slave Lake

Cabbage is usually straightforward to fit into the season in Slave Lake. Gardeners typically get more value from steady growth and timing than from worrying about whether the crop will finish.

Typical Planting Window

Excellent fit in this climate

Use the planting dates below for cabbage in Slave Lake.

Start indoors March 31
Typical planting window May 12 – May 26
Method Transplant
Typical days to maturity 70–90

Cabbage is usually started indoors around March 31 and planted outdoors during the normal local window of May 12 to May 26. Most varieties need about 70–90 days to reach maturity once they are in the garden.

Cabbage is usually easy to fit into the season in Slave Lake, and the real payoff is having enough room to size the crop properly and harvest at the stage you actually want.

The climate usually makes this crop possible without strain, but the difference between an average result and a strong one still comes from steady growth and harvesting at the right stage.

Best local strategy: Take advantage of the margin by managing for even sizing and a clean finish, not by getting casual about timing.

Can Cabbage Mature in Slave Lake?

Growing degree days measure how much useful warmth typically accumulates during the season. For cabbage, this helps estimate whether local heat accumulation is usually enough for the crop to reach maturity on time.

Available GDD (base 40) 2147
Typical crop GDD target 1000
Heat margin +1147

From the usual planting window, Slave Lake typically provides about 2147 growing degree days for cabbage. With a typical crop target of 1000, that leaves a heat margin of +1147. That large heat margin means the crop usually has no trouble reaching maturity here. In practice, planting timing mostly affects how comfortably the crop sizes up and when harvest is ready, not whether the crop can finish.

When Is It Too Late to Plant?

If planting later than usual, this table shows how much growing degree day heat is still available from each point in the season. For cabbage, it is most useful for judging how much freedom you still have to plant for quality, finish, and harvest goals as the season moves along.

Checkpoint Remaining GDD Heat margin Fit vs typical target
Apr 15 2296 +1296 Comfortable
May 1 2281 +1281 Comfortable
May 15 2192 +1192 Comfortable
Jun 1 2000 +1000 Comfortable
Jun 15 1785 +785 Comfortable
Jul 1 1492 +492 Comfortable

How Different Cabbage Varieties Affect Results

The season in Slave Lake usually supports most cabbage varieties comfortably, which means the more useful decision is what kind of crop you want rather than simply how fast it finishes.

Varieties that often fit well here include:

  • Golden Acre — a classic early cabbage with strong practical fit in shorter seasons
  • Early Jersey Wakefield — an early pointed cabbage that is useful when speed and spring harvests matter more than storage
  • Stonehead — reliable and approachable, especially where gardeners want a firm early head
  • Red Express — a faster red cabbage option for gardeners who want color without moving all the way into long-season storage types
  • Cheers — productive and strong where the season offers a comfortable cool run
  • Storage No. 4 — better suited where the growing window gives longer room for finishing

Best Cabbage Varieties for Slave Lake

Cabbage variety choice in Slave Lake is mostly about head size, storage quality, compactness, and how much time you want to give the crop before harvest.

May 26 local season starts September 16 frost pressure returns
Less heat used 2147 GDD available

Hover or tap the dots to see which recommended varieties use that much local heat.

For Slave Lake, start with Stonehead and Red Express for cabbage when you want reliable early cabbage or a faster red cabbage option. Choose Early Jersey Wakefield and Golden Acre when you want early pointed spring cabbage or early compact cabbage heads. Look at Storage No. 4 and Cheers when you specifically want storage cabbage or productive main-season cabbage.

Compare each variety’s heat need and maturity timing against the local frost-free window before choosing what to grow.

Fastest / most cushion

Early Jersey Wakefield Very early
800 GDD needed 2147 available before frost
May 26 September 16
Comfortable fit
Why this fit?

Local season fit: Early Jersey Wakefield leaves about 1347 GDD cushion against the normal Slave Lake crop heat estimate.

Best for: early pointed cabbage.

A quick pointed cabbage that is useful when speed and spring harvests matter more than storage.

Tradeoff: Not a storage-focused cabbage.

Golden Acre Very early
800 GDD needed 2147 available before frost
May 26 September 16
Comfortable fit
Why this fit?

Local season fit: Golden Acre leaves about 1347 GDD cushion against the normal Slave Lake crop heat estimate.

Best for: early compact heads.

A classic early cabbage that gives gardeners a practical short-season path to firm heads.

Tradeoff: Not the biggest or best storage cabbage.

Also realistic

Storage No. 4 Late
1150 GDD needed 2147 available before frost
May 26 September 16
Comfortable fit
Why this fit?

Local season fit: Storage No. 4 leaves about 997 GDD cushion against the normal Slave Lake crop heat estimate.

Best for: storage cabbage.

A longer-season cabbage better suited to places with enough room for a full finish.

Tradeoff: Needs a longer finish than early cabbage.

Cheers Mid-season
1000 GDD needed 2147 available before frost
May 26 September 16
Comfortable fit
Why this fit?

Local season fit: Cheers leaves about 1147 GDD cushion against the normal Slave Lake crop heat estimate.

Best for: productive main-season cabbage.

A strong cabbage choice where the season offers a comfortable cool run.

Tradeoff: Needs more room than compact early cabbage.

GDD comparisons are a planning shortcut, not a guarantee. Soil, watering, sowing depth, pests, transplant quality, and harvest goals still affect the final result.

Variety class Typical days to maturity Typical GDD need Local fit
Very early 60–70 800 Good fit
Early 70–80 900 Good fit
Mid-season 80–95 1000 Good fit
Late 95–110 1150 Good fit

Main risk: When this crop disappoints here, the problem is usually practical rather than climatic. Timing, steady growth, and harvest stage matter more than season length.

How Frost Affects Planting Dates for Cabbage in Slave Lake

Slave Lake usually has about 113 frost-free days, with a typical last spring frost around May 26 and a typical first fall frost around September 16.

Typical last spring frost May 26
Typical first fall frost September 16
Typical frost-free days 113
Minimum safe temperature 28°F / -2 °C

Cabbage is generally somewhat frost tolerant and temperatures below about 28°F ( -2 °C) can slow growth or damage plants.

Cabbage is usually tolerant enough of cool conditions that light frost is not the main concern. The more useful question is how early planting affects establishment and overall crop quality.

When this crop disappoints in Slave Lake, the issue is usually management rather than climate fit. Timing, consistency, and harvest decisions matter more than season length.

In Slave Lake, the local season usually gives cabbage plenty of breathing room when planting happens around May 5. For a better local margin, gardeners usually do best in south-facing walls, raised beds, sheltered backyards, and urban heat pockets. Cooler spots like open windy yards, low frost pockets, and exposed sites that lose heat quickly often make timing tighter. For cabbage, the best local sites often help the crop get moving earlier and make timing a little more forgiving.

Set up cabbage for steady growth and pest protection

The better results usually come from steady growth, pest protection, and avoiding early setbacks.

Transplant support

Strong young plants help avoid slow starts and uneven sizing.

Pest and weather protection

Brassicas and leafy crops often benefit from simple protection while they establish.

Even growth

Consistent moisture and spacing help the crop size evenly.

Recommendations are based on the local growing margin for this crop. As an Amazon Associate, we may earn from qualifying purchases.

For a broader local overview, see the Slave Lake planting guide. You can also use the Growing Degree Day Planner to test planting dates and crop timing.