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.

The best time to plant periwinkles in Tustin should be estimated by using the USDA zone info.

Planting Calendar for Periwinkles

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

Since periwinkles do not do well in cold weather it's important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Tustin 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. Any later than that and your periwinkles may not have a chance to really do well. 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

In Tustin the average date of last frost happens on January 31. You can expect an average low temperature of 30°F in the coldest months of winter.

Keep in mind that USDA zone info for Tustin may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Tustin you get surprised by a frost after January 31 be ready to protect your periwinkles in the event of one of those late frosts.

USDA Zone Info for Tustin

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 Tustin

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