The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Mason City it's a good idea to estimate when it's a good idea to plant hardy asters.

Planting Calendar for Hardy Asters

Frost tolerance for hardy asters:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Hardy Asters do ok in some cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant hardy asters in Mason City 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 hardy asters and expect a good harvest is probably August. If you wait any later than that and your hardy asters may not have a chance to really do well. If you are starting your hardy asters indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Mason City. In the coldest months of winter you should expect an average low temperature of -20°F.

Remember that USDA zone info for Mason City is not always accurate and the actual date of last frost changes from year to year. Half of the time in Mason City you get a frost after April 15 so always be ready to cover your hardy asters if you have a late frost.

USDA Zone Info for Mason City

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Mason City

You may be interested in your other planting guides for Mason City.