One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Algonquin you can figure out when it's the best time to plant sweet williams by referring to 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 are moderately cold tolerant which means that you can get them planted earlier than other frost tender plants.

The earliest that you can plant sweet williams in Algonquin 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 really do well. Starting your sweet williams indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Algonquin the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Algonquin is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Algonquin last frost occurs after April 15 so always be ready to protect your sweet williams if you have one of those late frosts.

USDA Zone Info for Algonquin

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 Algonquin

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