The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to determine when it's possible to plant monarda by referring to the USDA zone info for Port Huron.

Planting Calendar for Monarda

Frost tolerance for monarda:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Monarda can survive in mild cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant monarda in Port Huron 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 monarda and expect a good harvest is probably August. You probably don't want to wait any later than that or else your monarda may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your monarda indoors.

Last Frost Date

In Port Huron the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Port Huron is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Port Huron there is a last frost after April 15 be ready to protect your monarda in the event of a surprise late frost.

USDA Zone Info for Port Huron

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Port Huron

You may be interested in your other planting guides for Port Huron.