Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Rochester you can figure out when to plant hardy asters by using the USDA zone info.

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.

You can plant hardy asters just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant hardy asters in Rochester is April. However, you really should wait until May 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. You can get started a little bit earlier by starting your hardy asters indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Rochester. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Rochester is not always accurate the actual date of last frost changes from year to year. Since half of the time in Rochester last frost occurs after May 15 be ready to cover your hardy asters in the event of a late frost.

USDA Zone Info for Rochester

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 Rochester

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