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 opportunity to plant phlox in Columbus should be figured out by looking at the USDA zone info.

Planting Calendar for Phlox

Frost tolerance for phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since phlox are moderately cold tolerant you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant phlox in Columbus is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant phlox and expect a good harvest is probably September. Any later than that and your phlox may not have a chance to fully mature. Starting your phlox indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Columbus. You can expect an average low temperature of -20°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Columbus is an average and the actual date of last frost changes from year to year. Half of the time in Columbus it frosts late in the year after April 15 so just be sure to be ready to protect your phlox in the event of a late frost.

USDA Zone Info for Columbus

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Columbus

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