One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Tracy can be looked at to determine when it's the best time to plant periwinkles.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

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

The earliest that you can plant periwinkles in Tracy is March. However, you really should wait until April 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. You probably don't want to wait any later than that or else your periwinkles may not have a chance to fully mature. Starting your periwinkles indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is February 15 in Tracy. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Tracy is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Tracy last frost occurs after February 15 so make sure that you are ready to protect your periwinkles if you have a late frost.

USDA Zone Info for Tracy

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Tracy

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