One of the best tools that you have as gardeners to help us estimate 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.

The first chance to plant dahlia in Columbus can be figured out by checking out the USDA zone info.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably not a good idea to plant dahlia until after the last frost because they are not cold tolerant.

The earliest that you can plant dahlia in Columbus 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. If you wait any later than that and your dahlia may not have a chance to really do well. Starting your dahlia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Columbus the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Columbus is just an average the actual date of last frost changes from year to year. Since half of the time in Columbus there is a last frost after April 15 be ready to cover your dahlia in the event of one of those late frosts.

USDA Zone Info for Columbus

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 Columbus

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