The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 the best time to plant four o' clock is to use the USDA zone info for Plymouth.

Planting Calendar for Four O' Clock

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

Since four o' clock require warm weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant four o' clock in Plymouth 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. You probably don't want to wait any later than that or else your four o' clock may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your four o' clock indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Plymouth. In the coldest months of winter you can expect an average low temperature of -10°F.

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 Plymouth and it can change quite a bit from year to year. Since half of the time in Plymouth last frost occurs after April 15 be ready to protect your four o' clock in the event of a late frost.

USDA Zone Info for Plymouth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Plymouth

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