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

One way of getting a good idea when it's a good idea to plant dahlias is to use the USDA zone info for Mount Vernon.

Planting Calendar for Dahlias

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

You really shouldn't plant dahlias until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant dahlias in Mount Vernon 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 dahlias and expect a good harvest is probably August. Any later than that and your dahlias may not have a chance to fully mature. If you are starting your dahlias indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Mount Vernon. It might get as low as 0°F during the coldest months of winter.

Remember that USDA zone info for Mount Vernon is just an average and the actual date of last frost is different every year. Half of the time in Mount Vernon you get surprised by a frost after April 15 so make sure that you are prepared to cover your dahlias if you have a late frost.

USDA Zone Info for Mount Vernon

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 Mount Vernon

You may be interested in your other planting guides for Mount Vernon.