When to Plant Four-o-clock flower in Zone 3a

One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

The best time to plant four-o-clock flower in Zone 3a should be figured out by looking at the USDA zone info.


Planting Calendar for Four-o-clock flower

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

Four-o-clock flower are not cold tolerant which tells us that you must wait until it warms up after the last frost has passed before you can plant them.

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

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

Last Frost Date

The average date of last frost is May 15 in Zone 3a. It might get as low as -40°F during the coldest months of winter.

It's important to remember 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 is different every year. Half of the time in Zone 3a you get surprised by a frost after May 15 so make sure that you are ready to cover your four-o-clock flower in the event of a surprise 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.