Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to estimate when it's the best time to plant flower-of-an-hour by using the USDA zone info for Zone 3b.

Planting Calendar for Flower-of-an-Hour

Frost tolerance for flower-of-an-hour:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since flower-of-an-hour are barely cold tolerant you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant flower-of-an-hour in Zone 3b is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant flower-of-an-hour and expect a good harvest is probably August. If you wait any later than that and your flower-of-an-hour may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your flower-of-an-hour indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Zone 3b. In the coldest months of winter you should expect an average low temperature of -35°F.

Since the USDA zone info for Zone 3b is an average the actual date of last frost will vary from year to year. Half of the time in Zone 3b there is a last frost after May 15 so just be sure to be ready to protect your flower-of-an-hour if you have a surprise late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in your other planting guides for Zone 3b.