When to Plant Four O' Clock in Zone 3a

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when it's the best time to plant four o' clock in Zone 3a by reviewing the USDA zone info.

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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 it is important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant four o' clock
Possibly ok, but a risky time to plant four o' clock
Probably not a good time to plant four o' clock

The earliest that you can plant four o' clock in Zone 3a is May. However, you really should wait until June 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. Any later than that and your four o' clock may not have a chance to fully mature. If you are starting your four o' clock 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 May 15 in Zone 3a. You should expect an average low temperature of -40°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 3a and it will vary from year to year. Since half of the time in Zone 3a last frost occurs after May 15 be ready to protect your four o' clock if you have a late frost.

USDA Zone Info for Zone 3a

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-40°F
Highest Expected Low-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in Zone 3a

You may be interested in your other planting guides for Zone 3a.