Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Blue Island you can estimate when it's possible to plant sweet williams by checking out the USDA zone info.

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 means that you can plant them a little bit earlier than other frost tender plants.

The earliest that you can plant sweet williams in Blue Island 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 grow to maturity. You can get started a couple of weeks earlier by starting your sweet williams indoors.

Last Frost Date

The average date of last frost is April 15 in Blue Island. In the coldest months of winter you should expect an average low temperature of -10°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Blue Island and it will vary from year to year. Half of the time in Blue Island last frost occurs after April 15 so make sure that you are ready to protect your sweet williams in the event of one of those late frosts.

USDA Zone Info for Blue Island

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 Blue Island

You may be interested in your other planting guides for Blue Island.