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.

It's a good idea to estimate when it's a good idea to plant periwinkles by using the USDA zone info for Glendale.

Planting Calendar for Periwinkles

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

Since periwinkles do not do well in cold weather you need 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 Glendale 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. Starting your periwinkles indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Glendale the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Glendale and it can change quite a bit from year to year. Half of the time in Glendale you get a frost after February 15 so always be ready to cover your periwinkles in the event of a surprise late frost.

USDA Zone Info for Glendale

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 Glendale

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