One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's the best time to plant platycodon is to use the USDA zone info for Philadelphia.

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.

Platycodon are barely cold tolerant which means that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant platycodon in Philadelphia 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. You can get started a little bit earlier by starting your platycodon indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Philadelphia. It might get as low as 0°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Philadelphia and it can change quite a bit from year to year. Half of the time in Philadelphia you get surprised by a frost after April 15 so be sure to be ready to cover your platycodon in the event of a surprise late frost.

USDA Zone Info for Philadelphia

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Philadelphia

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