Climate-based pepper planting guide for Great Falls, Montana

When to Plant Peppers in Great Falls: Timing and Maturity Guide

In Great Falls, peppers are usually workable with enough season for solid results, but not so much room that timing stops mattering.

Typical Planting Window

Good fit in this climate

Use the planting dates below for peppers in Great Falls.

Start indoors March 18
Typical planting window May 22 – June 1
Method Transplant
Typical days to maturity 70–85

Gardeners usually start indoors around March 18 and plant outdoors from about May 22. Most varieties need about 70–85 days to reach maturity once they are in the garden.

Peppers are usually a solid option in Great Falls, but this is still a crop where delays or slower varieties can narrow the margin noticeably.

Great Falls usually gets into pepper planting season slightly earlier than many other Montana locations. That makes local site warmth more important than it would be where the seasonal margin is wider.

Best local strategy: Stay close to the normal transplant window and avoid giving up time early in the season.

Can Peppers Mature in Great Falls?

Growing degree days measure how much useful warmth the season provides. For warm-season crops like peppers, GDD helps show whether local heat accumulation is usually strong enough for the crop to grow steadily and finish before fall.

Available GDD (base 50) 1452
Typical crop GDD target 1300
Heat margin +152

From the usual planting window, Great Falls typically provides about 1452 growing degree days for peppers. With a typical crop target of 1300, that leaves a heat margin of +152. That heat margin usually gives the crop enough room to finish, but not so much that delays stop mattering. Timing and variety choice still affect how comfortably the crop fits.

GDD Checkpoints for Great Falls

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 1456 +156 Comfortable
Jun 1 1402 +102 Usually fits
Jun 15 1310 +10 Tight fit
Jul 1 1159 -141 Usually short

Best Pepper Varieties for Great Falls

In Great Falls, very early to mid-season pepper varieties are usually the best fit in a typical year. Slower choices can still work when gardeners want their specific qualities and do not give away margin through delay.

Varieties that often fit well here include:

Variety class Typical days to maturity Typical GDD need Local fit
Very early 60–70 950 Good fit
Early 65–75 1100 Good fit
Mid-season 75–85 1300 Workable
Late 85–100 1500 Tight

Main risk: Late planting or cool early conditions can still narrow the margin for slower pepper varieties.

How Frost Affects Peppers in Great Falls

Great Falls usually has about 148 frost-free days, with a typical last spring frost around May 6 and a typical first fall frost around October 1.

Typical last spring frost May 6
Typical first fall frost October 1
Typical frost-free days 148
Minimum safe temperature 32°F / 0 °C

Peppers are generally frost-tender and temperatures below about 32°F ( 0 °C) can slow growth or damage plants.

Peppers are much more exposed to frost risk, so the frost dates matter as real planting boundaries rather than rough planning markers.

The usual trouble comes from delayed planting or from choosing slower varieties when the local season would reward simpler, faster choices.

Peppers are usually workable in Great Falls, but local site warmth still influences how much margin they finish before the usual fall frost around October 1. Local gardens do not all warm and cool at the same pace. For a better local margin, gardeners usually do best in south-facing walls, sheltered gardens, raised beds, and sunnier urban lots. Cooler spots like low spots, exposed sites, and shadier yards often make timing tighter. For peppers, the main benefit is usually faster maturity and fruit that finishes more reliably on the plant.

Related crops

Related crops worth comparing for the same city:

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