The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Havre you can estimate when it's a good idea to plant creeping phlox by looking at the USDA zone info.

Planting Calendar for Creeping Phlox

Frost tolerance for creeping phlox:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Creeping Phlox are very cold tolerant which tells us that you can plant them much earlier than other frost tender plants.

The earliest that you can plant creeping phlox in Havre is March. However, you really should wait until April if you don't want to take any chances.

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

Last Frost Date

In Havre the average date of last frost happens on May 15. You can expect an average low temperature of -30°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Havre and it is different every year. Half of the time in Havre last frost occurs after May 15 so be sure to be ready to protect your creeping phlox if you have a late frost.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

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