Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of making a decision about when it's the best time to plant periwinkles is to look at the USDA zone info for Chino Hills.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Periwinkles require warm weather which tells us that you have to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant periwinkles in Chino Hills 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 periwinkles and expect a good harvest is probably September. If you wait any later than that and your periwinkles may not have a chance to grow to maturity. If you are starting your periwinkles 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 January 31 in Chino Hills. You should expect an average low temperature of 30°F in the coldest months of winter.

It's important to remember that USDA zone info for Chino Hills is an average and the actual date of last frost changes from year to year. Half of the time in Chino Hills it frosts late in the year after January 31 so always be ready to cover your periwinkles if you have a late frost.

USDA Zone Info for Chino Hills

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 Chino Hills

You may be interested in your other planting guides for Chino Hills.