One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

In Sterling you can figure out when it's a good idea to plant sweet williams by looking at 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.

You can plant sweet williams a little bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant sweet williams in Sterling 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Sterling. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Sterling is just an average the actual date of last frost changes from year to year. Half of the time in Sterling you get surprised by a frost after April 15 so always be ready to protect your sweet williams in the event of a late frost.

USDA Zone Info for Sterling

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Sterling

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