The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Marine City you should be able to estimate when it's possible to plant sweet williams.

Planting Calendar for Sweet Williams

Frost tolerance for sweet williams:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Sweet Williams do well in mild cold which tells us that you can plant them a little earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant sweet williams in Marine City 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 sweet williams and expect a good harvest is probably September. Any later than that and your sweet williams may not have a chance to really do well. Starting your sweet williams indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Marine City. You should expect an average low temperature of -10°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Marine City is just an average and the actual date of last frost is different every year. Since half of the time in Marine City last frost occurs after April 15 be ready to cover your sweet williams if you have one of those late frosts.

USDA Zone Info for Marine City

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 Marine City

You may be interested in your other planting guides for Marine City.