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 earliest that you can plant erysimum in Great Falls can be figured out by checking out the USDA zone info.

Planting Calendar for Erysimum

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

You can plant erysimum a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant erysimum in Great Falls 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 erysimum and expect a good harvest is probably August. Any later than that and your erysimum may not have a chance to fully mature. Starting your erysimum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Great Falls. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Great Falls is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Great Falls you get surprised by a frost after May 15 so always be ready to protect your erysimum if you have a surprise late frost.

USDA Zone Info for Great Falls

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 Great Falls

You may be interested in your other planting guides for Great Falls.