Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant cardinal flower in Plymouth can be figured out by using 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 has passed.

Since cardinal flower do not do well in cold weather it's important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant cardinal flower in Plymouth 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. If you wait any later than that and your cardinal flower may not have a chance to fully mature. If you are starting your cardinal flower indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Plymouth the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Plymouth is an average the actual date of last frost changes from year to year. Half of the time in Plymouth you get a frost after April 15 so make sure that you are ready to cover your cardinal flower if you have a surprise late frost.

USDA Zone Info for Plymouth

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Plymouth

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