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.

By checking out the USDA zone info for New Haven you will be able to figure out when to plant flower-of-an-hour.

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.

Flower-of-an-Hour are barely cold tolerant which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant flower-of-an-hour in New Haven is March. However, you really should wait until April 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. Any later than that and your flower-of-an-hour may not have a chance to fully mature. Starting your flower-of-an-hour indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in New Haven. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for New Haven is not always accurate the actual date of last frost is different every year. Half of the time in New Haven you get a frost after April 15 so be sure to be ready to protect your flower-of-an-hour in the event of a late frost.

USDA Zone Info for New Haven

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in New Haven

You may be interested in your other planting guides for New Haven.