One of the best tools that you have as gardeners to help us estimate 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.

By referring to the USDA zone info for Rockford you should be able to determine when you can 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 can survive in a little bit of 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 sweet williams in Rockford 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. If you wait 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 few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Rockford is an average the actual date of last frost is different every year. Since half of the time in Rockford it frosts late in the year after April 15 be ready to cover your sweet williams if you have a late frost.

USDA Zone Info for Rockford

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Rockford

You may be interested in your other planting guides for Rockford.