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 first chance to plant periwinkles in Redwood City can be estimated by checking out the USDA zone info.

Planting Calendar for Periwinkles

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

Periwinkles are not cold tolerant which means 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 Redwood City 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. If you wait any later than that and your periwinkles may not have a chance to grow to maturity. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Redwood City. In the coldest months of winter you should expect an average low temperature of 25°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Redwood City and it changes from year to year. Since half of the time in Redwood City last frost occurs after February 15 be ready to cover your periwinkles if you have one of those late frosts.

USDA Zone Info for Redwood City

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 Redwood City

You may be interested in your other planting guides for Redwood City.