Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Petaluma you can estimate when you can plant catharanthus 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.

You can not plant catharanthus until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant catharanthus in Petaluma 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 little bit earlier by starting your catharanthus indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Petaluma and it can change quite a bit from year to year. Since half of the time in Petaluma last frost occurs after February 15 be ready to cover your catharanthus if you have a late frost.

USDA Zone Info for Petaluma

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 Petaluma

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