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 earliest that you can plant catharanthus in Riverside should be estimated by using the USDA zone info.

Planting Calendar for Catharanthus

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

Catharanthus require warm weather which tells us that it is important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant catharanthus in Riverside 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 catharanthus and expect a good harvest is probably September. If you wait any later than that and your catharanthus may not have a chance to really do well. You can get started a couple of weeks earlier by starting your catharanthus indoors.

Last Frost Date

In Riverside the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Remember that USDA zone info for Riverside is just an average and the actual date of last frost changes from year to year. Half of the time in Riverside it frosts late in the year after February 15 so be sure to be ready to protect your catharanthus if you have a surprise late frost.

USDA Zone Info for Riverside

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 Riverside

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