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

A common way of making a decision about when to plant hardy asters is to use the USDA zone info for Chelsea.

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 moderate cold which means that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant hardy asters in Chelsea 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. You probably don't want to wait any later than that or else 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 all chance of frost has passed is on April 15 in Chelsea. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Chelsea is an average the actual date of last frost will vary from year to year. Half of the time in Chelsea you get surprised by a frost after April 15 so just be sure to be ready to protect your hardy asters in the event of one of those late frosts.

USDA Zone Info for Chelsea

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Chelsea

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