One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A common way of getting a good idea when it's a good idea to plant hardy asters is to consult the USDA zone info for Rosemead.

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 can survive in some cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hardy asters in Rosemead 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. Starting your hardy asters indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Rosemead. In the coldest months of winter you can expect an average low temperature of 30°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Rosemead and it changes from year to year. Half of the time in Rosemead there is a last frost after January 31 so make sure that you are ready to cover your hardy asters if you have a surprise late frost.

USDA Zone Info for Rosemead

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Rosemead

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