One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Harper Woods should be used to figure out when 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 moderate cold which tells us that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant sweet williams in Harper Woods 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 fully mature. Starting your sweet williams indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Harper Woods the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Keep in mind that USDA zone info for Harper Woods is an average and the actual date of last frost will vary from year to year. Since half of the time in Harper Woods there is a last frost after April 15 be ready to protect your sweet williams if you have one of those late frosts.

USDA Zone Info for Harper Woods

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 Harper Woods

You may be interested in your other planting guides for Harper Woods.