Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can estimate when it's the best time to plant catharanthus in Walnut 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.

Catharanthus are not cold tolerant which tells us that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant catharanthus in Walnut 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 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

On average the last frost is on January 31 in Walnut. It might get as low as 30°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Walnut and it changes from year to year. Half of the time in Walnut you get a frost after January 31 so make sure that you are prepared to cover your catharanthus in the event of a late frost.

USDA Zone Info for Walnut

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 Walnut

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