One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Hillsboro you can estimate when it's a good idea to plant hardy asters by looking at 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.

Hardy Asters are barely cold tolerant which means that you can get them planted just a bit earlier than other plants that might not handle the cold.

The earliest that you can plant hardy asters in Hillsboro 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. Any later than that and your hardy asters may not have a chance to fully mature. 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 Hillsboro. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Hillsboro is an average and the actual date of last frost will vary from year to year. Since half of the time in Hillsboro last frost occurs after April 15 be ready to cover your hardy asters if you have one of those late frosts.

USDA Zone Info for Hillsboro

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 Hillsboro

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