One of the first steps you take when you are estimating 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.

The first opportunity to plant sweet williams in Waterloo can be figured out by checking out 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 just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant sweet williams in Waterloo 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

The average date of last frost is April 15 in Waterloo. You should expect an average low temperature of -5°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Waterloo and it can change quite a bit from year to year. Half of the time in Waterloo it frosts late in the year after April 15 so make sure that you are prepared to protect your sweet williams if you have a surprise late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Waterloo

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