One of the best tools that you have as gardeners to help us determine 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.

The USDA zone info for Waterloo should be reviewed to figure out when you can plant snow-in summer.

Planting Calendar for Snow-in Summer

Frost tolerance for snow-in summer:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant snow-in summer a little earlier in the year because they are moderately cold tolerant.

The earliest that you can plant snow-in summer 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 snow-in summer and expect a good harvest is probably September. Any later than that and your snow-in summer may not have a chance to grow to maturity. If you are starting your snow-in summer indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Waterloo is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Waterloo there is a last frost after April 15 so make sure that you are ready to protect your snow-in summer 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.