Climate-based kale planting guide for Jackson, Wyoming

When to Plant Kale in Jackson

In Jackson, kale is usually a strong local fit. Most gardeners have some room to work with this crop rather than feeling close to the edge.

Typical Planting Window

Strong fit in this climate

Use the planting dates below for kale in Jackson.

Optional indoor start May 16
Typical planting window May 27 – June 16
Method Direct sow or transplant
Typical days to maturity 50–65

Kale can usually be started indoors around May 16 or sown directly during the normal local planting window of May 27 to June 16. Most varieties need about 50–65 days to reach maturity.

Kale is usually a dependable choice in Jackson. Normal timing and realistic variety choice are usually enough to produce dependable results.

What stronger local margin really changes is that gardeners can wait for a better-finished crop instead of harvesting defensively.

Best local strategy: Use the normal transplant window and prioritize healthy early growth, spacing, and even moisture.

Can Kale Mature in Jackson?

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

Available GDD (base 40) 1527
Typical crop GDD target 700
Heat margin +827

From the usual planting window, Jackson typically provides about 1527 growing degree days for kale. With a typical crop target of 700, that leaves a heat margin of +827. That heat margin usually gives the crop a dependable buffer, so gardeners have some flexibility in planting date and variety choice without pushing the crop close to the edge.

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. It is most useful for judging how much flexibility you still have before the crop starts losing margin.

Checkpoint Remaining GDD Heat margin Fit vs typical target
Apr 15 2345 +1645 Comfortable
May 1 2333 +1633 Comfortable
May 15 2262 +1562 Comfortable
Jun 1 2098 +1398 Comfortable
Jun 15 1915 +1215 Comfortable
Jul 1 1652 +952 Comfortable

How Different Kale Varieties Affect Results

Kale usually has enough season here that variety speed is not the main concern. In Jackson, the more useful decisions are leaf type, plant size, and how long you want harvest to continue into fall. For most gardeners, choosing the form they want to harvest matters more than small differences in maturity.

Varieties that often fit well here include:

  • Red Russian — fast and forgiving, especially where gardeners want an earlier leaf harvest
  • Siberian — cold-tolerant and useful when reliability matters more than a large curled plant
  • Winterbor — dependable and widely grown, with good fit for cool climates
  • Vates — compact and dependable, especially where gardeners want steady leaves without oversized plants
  • Lacinato — productive and popular, but usually a little slower to size up than the earliest kales
  • Redbor — colorful and ornamental, but chosen more for purple curled leaves than maximum speed

Best Kale Varieties for Jackson

Kale variety choice in Jackson is mostly about leaf type, plant size, harvest style, and how quickly you want usable leaves.

June 20 local season starts August 31 frost pressure returns
Less heat used 1527 GDD available

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

For Jackson, start with Winterbor and Vates for kale when you want a dependable curled kale for steady harvests or compact curled kale plants. Choose Red Russian and Siberian when you want earlier leafy harvests or cold-tolerant leafy kale. Look at Lacinato and Redbor when you specifically want larger dark leaves and a more substantial kale plant or purple curled leaves and ornamental color.

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

Fastest / most cushion

Red Russian Very early
600 GDD needed 1527 available before frost
June 20 August 31
Comfortable fit
Why this fit?

Local season fit: Red Russian leaves about 927 GDD cushion against the normal Jackson crop heat estimate.

Best for: fast leafy harvests.

A quick, forgiving kale that is useful when you want earlier leaf harvests and a wide margin in cooler seasons.

Tradeoff: Not the heaviest curled kale option.

Siberian Very early
600 GDD needed 1527 available before frost
June 20 August 31
Comfortable fit
Why this fit?

Local season fit: Siberian leaves about 927 GDD cushion against the normal Jackson crop heat estimate.

Best for: cold-tolerant leafy kale.

A hardy leafy kale that is useful when reliability and cool-weather harvests matter more than a large curled plant.

Tradeoff: More about reliability than refined leaf texture.

Also realistic

Lacinato Mid-season
825 GDD needed 1527 available before frost
June 20 August 31
Comfortable fit
Why this fit?

Local season fit: Lacinato leaves about 702 GDD cushion against the normal Jackson crop heat estimate.

Best for: fuller dark-leaf harvests.

A popular dark-leaf kale that can be productive, but usually needs a little more time to size up than the fastest types.

Tradeoff: Usually needs more time to size up than faster kale choices.

Redbor Mid-season
825 GDD needed 1527 available before frost
June 20 August 31
Comfortable fit
Why this fit?

Local season fit: Redbor leaves about 702 GDD cushion against the normal Jackson crop heat estimate.

Best for: purple curled kale.

A colorful curled kale that is better chosen for cold-season color and ornamental value than for maximum speed.

Tradeoff: Chosen for color more than speed.

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 45–50 600 Good fit
Early 50–60 700 Good fit
Mid-season 60–75 825 Good fit

Main risk: The usual setback here is giving away seasonal margin through late planting, slow early growth, or slower variety choice than the crop really needs.

How Frost Affects Planting Dates for Kale in Jackson

Jackson usually has about 72 frost-free days, with a typical last spring frost around June 20 and a typical first fall frost around August 31.

Typical last spring frost June 20
Typical first fall frost August 31
Typical frost-free days 72
Minimum safe temperature 25°F / -4 °C

Kale is generally frost tolerant and temperatures below about 25°F ( -4 °C) can slow growth or damage plants.

Kale 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.

Problems here usually come from giving up part of the season through late planting, weak early growth, or slower variety choice than the crop really needs.

In Jackson, kale already has plenty of seasonal room when planted around June 13. In practical terms, the best spots are usually south-facing walls, sheltered gardens, raised beds, and sunnier urban lots. Cooler spots like low spots, exposed sites, and shadier yards are more likely to stay cooler and be less forgiving. For kale, warmer local sites usually help the crop get established earlier and grow a little more steadily.

Set up kale 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 Jackson planting guide. You can also use the Growing Degree Day Planner to test planting dates and crop timing.