One of the first steps you take when you are determining 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 referring to the USDA zone info for Urbandale it's possible to figure out 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.

You can plant sweet williams just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant sweet williams in Urbandale 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. You can get started a couple of weeks earlier by starting your sweet williams indoors.

Last Frost Date

On average the last frost is on April 15 in Urbandale. In the coldest months of winter you can expect an average low temperature of -20°F.

Just be sure to remember that USDA zone info for Urbandale is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Urbandale last frost occurs after April 15 be ready to cover your sweet williams if you have one of those late frosts.

USDA Zone Info for Urbandale

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 Urbandale

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