The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant dahlia in Worthington can be estimated 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 are not cold tolerant you need to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant dahlia in Worthington is May. However, you really should wait until June 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. You can get started a couple of weeks earlier by starting your dahlia indoors.

Last Frost Date

On average all chance of frost has passed is on May 15 in Worthington. In the coldest months of winter you can expect an average low temperature of -25°F.

It's important to remember that USDA zone info for Worthington may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Worthington you get a frost after May 15 be ready to cover your dahlia in the event of a surprise late frost.

USDA Zone Info for Worthington

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Worthington

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