Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant onions in Havre can be determined by using the USDA zone info.

Planting Calendar for Onions

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

Onions are one of those plants that can tolerate quite a bit of cold weather which tells us that you can plant them a quite a bit earlier than more sensitive plants.

The earliest that you can plant onions 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 onions and expect a good harvest is probably August. Any later than that and your onions may not have a chance to fully mature. You can get started a few weeks earlier by starting your onions indoors.

Last Frost Date

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

Since the USDA zone info for Havre is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Havre it frosts late in the year after May 15 be ready to cover your onions in the event of one of those late frosts.

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.