One of the best tools that you have as gardeners to help us figure out 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 can determine when it's the best time to plant catharanthus in Smithfield by referring to the USDA zone info.

Planting Calendar for Catharanthus

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

You should not plant catharanthus until after the last frost because they are not cold tolerant.

The earliest that you can plant catharanthus in Smithfield 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. You probably don't want to wait any later than that or else your catharanthus may not have a chance to fully mature. Starting your catharanthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Smithfield. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Smithfield is an average and the actual date of last frost is different every year. Half of the time in Smithfield there is a last frost after March 15 so always be ready to protect your catharanthus if you have a surprise late frost.

USDA Zone Info for Smithfield

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Smithfield

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