One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when to plant cardinal flower in Prosser by looking at the USDA zone info.

Planting Calendar for Cardinal Flower

Frost tolerance for cardinal flower:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since cardinal flower are not cold tolerant you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant cardinal flower in Prosser is April. However, you really should wait until May 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 August. 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 Prosser the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Prosser 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 Prosser it frosts late in the year after April 15 so be sure to be ready to cover your cardinal flower if you have one of those late frosts.

USDA Zone Info for Prosser

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Prosser

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