When can I plant Four-o-clock flower in Zone 3b

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

The best time to plant four-o-clock flower in Zone 3b can be determined by using the USDA zone info.


Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower: Not tolerant of frost.
When you should plant them: After all chance of frost has passed.

Since four-o-clock flower are not cold tolerant you need to wait until after all chance of 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 3b 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. You probably don't want to wait any later than that or else your four-o-clock flower may not have a chance to really do well. If you are starting your four-o-clock flower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Zone 3b the average date of last frost happens on May 15. In the coldest months of winter we should expect an average low temperature of -35°F.

Since the USDA zone info for Zone 3b is just an average our actual date of last frost can change quite a bit from year to year. Half of the time in Zone 3b last frost occurs after May 15 so make sure that you are ready to protect your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-35°F
Highest Expected Low-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in our other planting guides for Zone 3b.