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

The first chance to plant asters in Zone 6a should be figured out by using the USDA zone info.

Planting Calendar for Asters

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

Asters are moderately cold tolerant which means that you can get them planted earlier than other frost tender plants.

The earliest that you can plant asters in Zone 6a is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant asters and expect a good harvest is probably September. Any later than that and your asters may not have a chance to really do well. Starting your asters indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Zone 6a. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Zone 6a is an average the actual date of last frost will vary from year to year. Half of the time in Zone 6a last frost occurs after April 15 so make sure that you are prepared to protect your asters if you have one of those late frosts.

USDA Zone Info for Zone 6a

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Zone 6a

You may be interested in your other planting guides for Zone 6a.