One of the first steps you take when you are determining your gardening schedule is find your 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.

In Mankato you can estimate when it's the best time to plant helianthemum by checking out the USDA zone info.

Planting Calendar for Helianthemum

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

Since helianthemum are moderately cold tolerant you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant helianthemum in Mankato 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 helianthemum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your helianthemum may not have a chance to really do well. Starting your helianthemum indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Mankato and it can change quite a bit from year to year. Half of the time in Mankato you get a frost after May 15 so make sure that you are ready to protect your helianthemum in the event of a surprise late frost.

USDA Zone Info for Mankato

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 Mankato

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