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.

One way of estimating when it's the best time to plant dahlias is to look at the USDA zone info for Rochester.

Planting Calendar for Dahlias

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

It's not a good idea to plant dahlias until after all chance of frost has passed because they require warm weather.

The earliest that you can plant dahlias in Rochester 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. You probably don't want to wait any later than that or else your dahlias may not have a chance to grow to maturity. 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

On average the last frost when the weather gets warmer is on April 15 in Rochester. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Rochester is just an average the actual date of last frost changes from year to year. Half of the time in Rochester there is a last frost after April 15 so make sure that you are prepared to protect your dahlias if you have one of those late frosts.

USDA Zone Info for Rochester

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 Rochester

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