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.

By checking out the USDA zone info for Havre it's a good idea to figure out when it's possible to plant pampas grass.

Planting Calendar for Pampas Grass

Frost tolerance for pampas grass:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since pampas grass require warm weather it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

On average all chance of frost has passed is on May 15 in Havre. You should expect an average low temperature of -30°F in the coldest months of winter.

Since the USDA zone info for Havre is just an average the actual date of last frost changes from year to year. Since half of the time in Havre you get surprised by a frost after May 15 be ready to protect your pampas grass if you have a surprise 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.