One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. 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 dahlias by checking out the USDA zone info for Louisville.

Planting Calendar for Dahlias

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

You can not plant dahlias until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant dahlias in Louisville 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. You can get started a little bit earlier by starting your dahlias indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Louisville. You can expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Louisville is just an average and the actual date of last frost will vary from year to year. Since half of the time in Louisville it frosts late in the year after April 15 be ready to cover your dahlias in the event of a surprise late frost.

USDA Zone Info for Louisville

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 Louisville

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