One of the best tools that you have as gardeners to help us determine 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.

In Sonora you can determine when it's the best time to plant cardinal flower by reviewing the USDA zone info.

Planting Calendar for Cardinal Flower

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

It's a bad idea to plant cardinal flower until after the last frost when the weather gets warmer because they do not do well in cold weather.

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

Last Frost Date

In Sonora the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

Always keep in mind that USDA zone info for Sonora is not always accurate and 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 just be sure to be ready to cover your cardinal flower 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.