The USDA Zone info is a great tool for gardeners to help us determine your gardening 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 possible to plant periwinkles is to check out the USDA zone info for Fortuna.

Planting Calendar for Periwinkles

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

Periwinkles do not do well in cold weather which tells us that you must wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in Fortuna 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. Any later than that and your periwinkles may not have a chance to fully mature. If you are starting your periwinkles indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Fortuna. It might get as low as 25°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Fortuna is an average and the actual date of last frost is different every year. Since half of the time in Fortuna there is a last frost after February 15 be ready to protect your periwinkles in the event of a surprise late frost.

USDA Zone Info for Fortuna

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 Fortuna

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