Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Bozeman can be reviewed to figure out when it's a good idea to plant portulaca.

Planting Calendar for Portulaca

Frost tolerance for portulaca:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You can not plant portulaca until after the last frost because they require warm weather.

The earliest that you can plant portulaca in Bozeman is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant portulaca and expect a good harvest is probably August. Any later than that and your portulaca may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your portulaca indoors.

Last Frost Date

The average date of last frost is May 15 in Bozeman. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Bozeman may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Bozeman there is a last frost after May 15 be ready to protect your portulaca in the event of one of those late frosts.

USDA Zone Info for Bozeman

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Bozeman

You may be interested in your other planting guides for Bozeman.