Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. 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 figure out when it's a good idea to plant platycodon by referring to the USDA zone info for Sunnyvale.

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 slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant platycodon in Sunnyvale 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. You probably don't want to wait any later than that or else your platycodon may not have a chance to fully mature. If you are starting your platycodon indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Sunnyvale. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Sunnyvale is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Sunnyvale it frosts late in the year after February 15 be ready to cover your platycodon in the event of a surprise late frost.

USDA Zone Info for Sunnyvale

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Sunnyvale

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