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

You should be able to estimate when it's possible to plant cardinal flower by referring to the USDA zone info for Watertown.

Planting Calendar for Cardinal Flower

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

You can not plant cardinal flower until after all chance of frost has passed because they require warm weather.

The earliest that you can plant cardinal flower in Watertown 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. You probably don't want to wait any later than that or else your cardinal flower may not have a chance to really do well. Starting your cardinal flower indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Watertown. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Watertown is an average the actual date of last frost will vary from year to year. Half of the time in Watertown it frosts late in the year after April 15 so just be sure to be ready to protect your cardinal flower in the event of a late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 6b.

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

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

Plants to Grow in Watertown

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