Before planting it is a good idea to find your USDA Zone info to figure out 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.

You can estimate when to plant dahlia in Manhattan by checking out the USDA zone info.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since dahlia do not do well in cold weather you must wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant dahlia in Manhattan 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. Any later than that and your dahlia may not have a chance to fully mature. If you are starting your dahlia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Manhattan. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Manhattan may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Manhattan there is a last frost after April 15 be ready to cover your dahlia if you have a surprise late frost.

USDA Zone Info for Manhattan

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Manhattan

You may be interested in your other planting guides for Manhattan.