When can I plant Four-o-clock flower in Zone 5b

One of the first steps we take when we are figuring out our gardening schedule is find our USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

A common way of figuring out when you can plant four-o-clock flower is to look at the USDA zone info for Zone 5b.


Planting Calendar for Four-o-clock flower

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

Four-o-clock flower do not do well in cold weather which tells us that it is important to wait until it warms up 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 5b 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 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. If you are starting your four-o-clock flower indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Zone 5b the average date of last frost happens on April 15. In the coldest months of winter we should expect an average low temperature of -15°F.

Since the USDA zone info for Zone 5b is an average our actual date of last frost changes from year to year. Half of the time in Zone 5b last frost occurs after April 15 so make sure that you are ready to protect your four-o-clock flower in the event of a late frost.

USDA Zone Info for Zone 5b

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 Zone 5b

You may be interested in our other planting guides for Zone 5b.