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.

The first opportunity to plant asters in Tempe should be figured out by checking out 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.

You can plant asters just a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant asters in Tempe is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant asters and expect a good harvest is probably October. If you wait any later than that and your asters may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your asters indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Tempe. In the coldest months of winter you can expect an average low temperature of 25°F.

Since the USDA zone info for Tempe is just an average the actual date of last frost is different every year. Half of the time in Tempe there is a last frost after February 15 so just be sure to be ready to protect your asters in the event of a surprise late frost.

USDA Zone Info for Tempe

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 Tempe

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