One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. 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 argyranthemum in Thief River Falls should be figured out by using the USDA zone info.

Planting Calendar for Argyranthemum

Frost tolerance for argyranthemum:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Argyranthemum do not do well in cold weather which tells us that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant argyranthemum in Thief River Falls is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant argyranthemum and expect a good harvest is probably August. If you wait any later than that and your argyranthemum may not have a chance to fully mature. If you are starting your argyranthemum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Thief River Falls. In the coldest months of winter you can expect an average low temperature of -35°F.

Since the USDA zone info for Thief River Falls is an average the actual date of last frost will vary from year to year. Since half of the time in Thief River Falls last frost occurs after May 15 be ready to cover your argyranthemum if you have a late frost.

USDA Zone Info for Thief River Falls

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Thief River Falls

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