Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Sullivan can be used to estimate when to plant platycodon.

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.

Since platycodon are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant platycodon in Sullivan 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. Any later than that and your platycodon may not have a chance to really do well. If you are starting your platycodon indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Sullivan. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Sullivan is an average the actual date of last frost changes from year to year. Half of the time in Sullivan it frosts late in the year after April 15 so make sure that you are ready to protect your platycodon if you have a surprise late frost.

USDA Zone Info for Sullivan

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Sullivan

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