One of the first steps you take when you are figuring out 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 looking at the USDA zone info for River Grove it's possible to figure out 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 can survive in a little bit of cold which means 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 River Grove 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. You probably don't want to wait any later than that or else 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

The average date of last frost is April 15 in River Grove. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for River Grove is an average the actual date of last frost can change quite a bit from year to year. Half of the time in River Grove there is a last frost after April 15 so be sure to be ready to protect your sweet williams if you have a surprise late frost.

USDA Zone Info for River Grove

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 River Grove

You may be interested in your other planting guides for River Grove.