The USDA Zone info is a great tool for gardeners to help us figure out 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.

You can determine when it's possible to plant vinca vine in Havre by referring to the USDA zone info.

Planting Calendar for Vinca Vine

Frost tolerance for vinca vine:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant vinca vine a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant vinca vine 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 vinca vine and expect a good harvest is probably August. If you wait any later than that and your vinca vine may not have a chance to grow to maturity. If you are starting your vinca vine indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Remember that USDA zone info for Havre may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Havre you get a frost after May 15 be ready to protect your vinca vine 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.