Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when it's the best time to plant dahlia by reviewing the USDA zone info for New Haven.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Dahlia do not do well in cold weather which tells us that it is important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant dahlia 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 dahlia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlia may not have a chance to really do well. If you are starting your dahlia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In New Haven the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for New Haven is an average the actual date of last frost changes from year to year. Half of the time in New Haven it frosts late in the year after April 15 so be sure to be ready to cover your dahlia 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.