One of the first steps you take when you are determining 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.

By using the USDA zone info for Port Huron it's possible to figure out when to plant alyssum.

Planting Calendar for Alyssum

Frost tolerance for alyssum:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant alyssum much earlier in the year because they are very cold tolerant.

The earliest that you can plant alyssum in Port Huron is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant alyssum and expect a good harvest is probably September. Any later than that and your alyssum may not have a chance to fully mature. You can get started a few weeks earlier by starting your alyssum indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Port Huron. You can expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Port Huron is not always accurate and the actual date of last frost is different every year. Half of the time in Port Huron last frost occurs after April 15 so be sure to be ready to protect your alyssum 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.