One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You can determine when it's possible to plant sunflowers in New Haven by using the USDA zone info.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Sunflowers require warm weather which means that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant sunflowers in New Haven 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 sunflowers and expect a good harvest is probably August. Any later than that and your sunflowers may not have a chance to grow to maturity. Starting your sunflowers 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 New Haven. In the coldest months of winter you can expect an average low temperature of 0°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for New Haven and it is different every year. Since half of the time in New Haven you get surprised by a frost after April 15 be ready to protect your sunflowers in the event of one of those late frosts.

USDA Zone Info for New Haven

Here is the info for USDA Zone 7a.

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

This means that on a really cold year, the coldest it will get is 0°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.