The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 Surprise can be determined by referring to 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.

Since periwinkles require warm weather it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant periwinkles in Surprise 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 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 Surprise the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Surprise is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Surprise last frost occurs after February 15 be ready to cover your periwinkles if you have a surprise late frost.

USDA Zone Info for Surprise

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 Surprise

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