When can I plant Calibrachoa in Zone 4a

One of the first steps we take when we are figuring out our gardening schedule is find our USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

By checking out the USDA zone info for Zone 4a it's a good idea to determine when it's the best time to plant calibrachoa.


Planting Calendar for Calibrachoa

Frost tolerance for calibrachoa: Tolerant of a very small amount of frost.
When you should plant them: Up to 3 weeks before last frost.

Calibrachoa are barely cold tolerant which tells us that you can start planting them slightly earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant calibrachoa
Possibly ok, but a risky time to plant calibrachoa
Probably not a good time to plant calibrachoa

The earliest that you can plant calibrachoa in Zone 4a 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 calibrachoa and expect a good harvest is probably August. If you wait any later than that and your calibrachoa may not have a chance to grow to maturity. You can get started a little bit earlier by starting your calibrachoa indoors.

Last Frost Date

The average date of last frost is May 15 in Zone 4a. We can expect an average low temperature of -30°F in the coldest months of winter.

It's important to remember that USDA zone info for Zone 4a may not be accurate from year to year and our actual date of last frost is different every year. Half of the time in Zone 4a we get a frost after May 15 so just be sure to be ready to protect your calibrachoa in the event of a surprise late frost.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-30°F
Highest Expected Low-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in our other planting guides for Zone 4a.