The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when to plant four o' clock is to examine the USDA zone info for South Portland.

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.

Four O' Clock are not cold tolerant which tells us that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant four o' clock in South Portland 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 little bit earlier by starting your four o' clock indoors.

Last Frost Date

On average the last frost is on April 15 in South Portland. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for South Portland is not always accurate the actual date of last frost is different every year. Half of the time in South Portland you get a frost after April 15 so make sure that you are prepared to cover your four o' clock in the event of a late frost.

USDA Zone Info for South Portland

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 South Portland

You may be interested in your other planting guides for South Portland.