The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Walnut it's a good idea to estimate when it's the best time 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.

Platycodon do well in very little cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant platycodon in Walnut 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. If you wait 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

On average the last frost when the weather gets warmer is on January 31 in Walnut. In the coldest months of winter you should expect an average low temperature of 30°F.

Keep in mind that USDA zone info for Walnut is just an average and the actual date of last frost is different every year. Since half of the time in Walnut you get surprised by a frost after January 31 be ready to cover your platycodon if you have a surprise late frost.

USDA Zone Info for Walnut

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 Walnut

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