The USDA Zone info is a great tool for gardeners to help us determine 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 Roma should be figured out by checking out the USDA zone info.

Planting Calendar for Catharanthus

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

Since catharanthus are not cold tolerant it is necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant catharanthus in Roma 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. You probably don't want to wait any later than that or else your catharanthus may not have a chance to really do well. If you are starting your catharanthus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Roma. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Roma is an average the actual date of last frost changes from year to year. Since half of the time in Roma you get surprised by a frost after February 15 be ready to cover your catharanthus in the event of a late frost.

USDA Zone Info for Roma

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 Roma

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