One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A common way of estimating when to plant sorrel is to refer to the USDA zone info for Havre.

Planting Calendar for Sorrel

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

Since sorrel are moderately cold tolerant you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant sorrel 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 sorrel and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sorrel may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your sorrel indoors.

Last Frost Date

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

Remember that USDA zone info for Havre may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Havre there is a last frost after May 15 so just be sure to be ready to protect your sorrel 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.