One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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 figure out when it's possible to plant catharanthus by referring to the USDA zone info for Gridley.

Planting Calendar for Catharanthus

Frost tolerance for catharanthus:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Catharanthus require warm weather which tells us that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant catharanthus in Gridley 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 fully mature. 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 Gridley. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Gridley is just an average the actual date of last frost will vary from year to year. Half of the time in Gridley it frosts late in the year after February 15 so make sure that you are prepared to protect your catharanthus in the event of a late frost.

USDA Zone Info for Gridley

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 Gridley

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