One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when you can plant periwinkles by referring to the USDA zone info for West Covina.

Planting Calendar for Periwinkles

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

Since periwinkles are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant periwinkles in West Covina is February. However, you really should wait until March 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 really do well. Starting your periwinkles indoors is a great way to get them started a little bit earlier.

Last Frost Date

In West Covina the average date of last frost happens on January 31. In the coldest months of winter you can expect an average low temperature of 30°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for West Covina and it can change quite a bit from year to year. Half of the time in West Covina last frost occurs after January 31 so always be ready to protect your periwinkles in the event of a late frost.

USDA Zone Info for West Covina

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in West Covina

You may be interested in your other planting guides for West Covina.