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 should be able to determine when it's a good idea to plant catharanthus by using the USDA zone info for Rome.

Planting Calendar for Catharanthus

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

It's a bad idea to plant catharanthus until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant catharanthus in Rome is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant catharanthus and expect a good harvest is probably August. If you wait any later than that and your catharanthus may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your catharanthus indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Rome. It might get as low as -20°F during the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Rome and it can change quite a bit from year to year. Half of the time in Rome you get surprised by a frost after April 15 so just be sure to be ready to protect your catharanthus in the event of a surprise late frost.

USDA Zone Info for Rome

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Rome

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