The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to figure out when it's possible to plant sunflowers by looking at the USDA zone info for New Ulm.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You should not plant sunflowers until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant sunflowers in New Ulm 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 sunflowers and expect a good harvest is probably August. Any later than that and your sunflowers may not have a chance to really do well. You can get started a little bit earlier by starting your sunflowers indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in New Ulm. It might get as low as -25°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for New Ulm and it changes from year to year. Since half of the time in New Ulm it frosts late in the year after May 15 be ready to protect your sunflowers in the event of a surprise late frost.

USDA Zone Info for New Ulm

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 New Ulm

You may be interested in your other planting guides for New Ulm.