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

You should be able to determine when it's a good idea to plant platycodon by using the USDA zone info for Columbus.

Planting Calendar for Platycodon

Frost tolerance for platycodon:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant platycodon just a tiny bit earlier in the year because they do ok in moderate cold.

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

The last month that you can plant platycodon and expect a good harvest is probably August. If you wait any later than that and your platycodon may not have a chance to fully mature. Starting your platycodon indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Columbus. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Columbus is an average the actual date of last frost will vary from year to year. Half of the time in Columbus it frosts late in the year after March 15 so be sure to be ready to protect your platycodon in the event of a surprise late frost.

USDA Zone Info for Columbus

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Columbus

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