Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Oregon you can estimate when it's possible to plant asters by looking at 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.

Since asters are moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant asters in Oregon 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 fully mature. You can get started a couple of weeks earlier by starting your asters indoors.

Last Frost Date

On average the last frost is on April 15 in Oregon. You should expect an average low temperature of -5°F in the coldest months of winter.

Remember that USDA zone info for Oregon is just an average and the actual date of last frost is different every year. Since half of the time in Oregon you get a frost after April 15 be ready to cover your asters in the event of one of those late frosts.

USDA Zone Info for Oregon

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 Oregon

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