Before planting it is a good idea to find your USDA Zone info to figure out 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.

The USDA zone info for Helena should be read to figure out when it's the best time to plant sorrel.

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 one of those plants that can tolerate a little bit of cold weather you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant sorrel in Helena 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. Any later than that and your sorrel may not have a chance to really do well. You can get started a little bit earlier by starting your sorrel indoors.

Last Frost Date

In Helena the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that USDA zone info for Helena is not always accurate and the actual date of last frost is different every year. Half of the time in Helena last frost occurs after May 15 so just be sure to be ready to cover your sorrel if you have one of those late frosts.

USDA Zone Info for Helena

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Helena

You may be interested in your other planting guides for Helena.