The USDA Zone info is a great tool for gardeners to help us figure out 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 earliest that you can plant impatiens in Sonora can be determined by reviewing the USDA zone info.

Planting Calendar for Impatiens

Frost tolerance for impatiens:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since impatiens require warm weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant impatiens in Sonora is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant impatiens and expect a good harvest is probably September. If you wait any later than that and your impatiens may not have a chance to fully mature. Starting your impatiens indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Sonora. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Sonora is an average the actual date of last frost changes from year to year. Since half of the time in Sonora last frost occurs after February 15 be ready to cover your impatiens if you have one of those late frosts.

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.