The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Sonora should be reviewed to determine when it's a good idea to plant chrysanthemums.

Planting Calendar for Chrysanthemums

Frost tolerance for chrysanthemums:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since chrysanthemums are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant chrysanthemums in Sonora 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 chrysanthemums and expect a good harvest is probably September. Any later than that and your chrysanthemums may not have a chance to grow to maturity. If you are starting your chrysanthemums indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Sonora the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Sonora may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Sonora last frost occurs after February 15 so make sure that you are ready to cover your chrysanthemums if you have a surprise late frost.

USDA Zone Info for Sonora

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Sonora

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