One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when it's possible to plant platycodon is to refer to the USDA zone info for San Carlos.

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 one of those plants that can tolerate a tiny bit of cold weather which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant platycodon in San Carlos 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 platycodon and expect a good harvest is probably September. Any later than that and your platycodon may not have a chance to grow to maturity. If you are starting your platycodon indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In San Carlos the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Keep in mind that USDA zone info for San Carlos is not always accurate and the actual date of last frost changes from year to year. Half of the time in San Carlos you get a frost after January 31 so make sure that you are prepared to protect your platycodon in the event of a late frost.

USDA Zone Info for San Carlos

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Carlos

You may be interested in your other planting guides for San Carlos.