One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when it's possible to plant trifolium is to examine the USDA zone info for Smithfield.

Planting Calendar for Trifolium

Frost tolerance for trifolium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Trifolium are barely cold tolerant which means that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant trifolium in Smithfield 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 trifolium and expect a good harvest is probably August. Any later than that and your trifolium may not have a chance to really do well. If you are starting your trifolium indoors then you might be able to get away with starting them a couple of 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.

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