Before planting it is a good idea to find your USDA Zone info to estimate your garden 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 four o' clock in Smithfield can be determined by using the USDA zone info.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant four o' clock until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant four o' clock 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 four o' clock and expect a good harvest is probably August. If you wait any later than that and your four o' clock may not have a chance to really do well. You can get started a few weeks earlier by starting your four o' clock indoors.

Last Frost Date

The average date of last frost is April 15 in Smithfield. In the coldest months of winter you should expect an average low temperature of -15°F.

It's important to 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 Smithfield and it can change quite a bit from year to year. Since half of the time in Smithfield you get a frost after April 15 be ready to cover your four o' clock if you have one of those late frosts.

USDA Zone Info for Smithfield

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

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

Plants to Grow in Smithfield

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