When to Plant Four-o-clock flower in Zone 5a

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

In Zone 5a you can determine when you can plant four-o-clock flower by referring to 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.

It's a bad idea to plant four-o-clock flower until after the last frost when the weather gets warmer because they are not cold tolerant.

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 5a 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 fully mature. 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

On average all chance of frost has passed is on April 15 in Zone 5a. In the coldest months of winter you should expect an average low temperature of -20°F.

Just be sure to remember that USDA zone info for Zone 5a is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 5a you get a frost after April 15 be ready to protect your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Zone 5a

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Zone 5a

You may be interested in your other planting guides for Zone 5a.