One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Westminster you can determine when it's possible 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 tend to make it in some cold which means that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hardy asters in Westminster 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 fully mature. If you are starting your hardy asters indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Westminster the average date of last frost happens on January 31. You can expect an average low temperature of 35°F in the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Westminster and it is different every year. Half of the time in Westminster you get a frost after January 31 so make sure that you are prepared to protect your hardy asters in the event of a surprise late frost.

USDA Zone Info for Westminster

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Westminster

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