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.

The first opportunity to plant hardy asters in Oroville can be estimated 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.

Hardy Asters do ok in moderate cold which tells us that you can plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant hardy asters in Oroville 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 hardy asters and expect a good harvest is probably September. You probably don't want to wait any later than that or else your hardy asters may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hardy asters indoors.

Last Frost Date

In Oroville the average date of last frost happens on February 15. You can expect an average low temperature of 25°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Oroville and it changes from year to year. Since half of the time in Oroville there is a last frost after February 15 be ready to protect your hardy asters if you have a surprise late frost.

USDA Zone Info for Oroville

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°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 30°F.

Plants to Grow in Oroville

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