One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Havre you should be able to estimate when it's possible to plant asparagus fern.

Planting Calendar for Asparagus Fern

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

Since asparagus fern are not cold tolerant it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant asparagus fern 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 asparagus fern and expect a good harvest is probably August. Any later than that and your asparagus fern may not have a chance to really do well. Starting your asparagus fern indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Havre is an average the actual date of last frost will vary from year to year. Since half of the time in Havre you get a frost after May 15 be ready to cover your asparagus fern in the event of 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.