When can I plant Primula in Zone 4a

The USDA Zone info is a great tool for gardeners to help us figure out our gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

The first opportunity to plant primula in Zone 4a should be estimated by using the USDA zone info.


Planting Calendar for Primula

Frost tolerance for primula: Very tolerant of frost.
When you should plant them: Up to 7 weeks before last frost.

Primula are very cold tolerant which tells us that you can plant them a quite a bit earlier than other frost tender plants.

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

The earliest that you can plant primula in Zone 4a is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant primula and expect a good harvest is probably August. If you wait any later than that and your primula may not have a chance to fully mature. Starting your primula indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Zone 4a the average date of last frost happens on May 15. In the coldest months of winter we can expect an average low temperature of -30°F.

Always keep in mind that USDA zone info for Zone 4a is an average and our actual date of last frost is different every year. Half of the time in Zone 4a it frosts late in the year after May 15 so make sure that you are prepared to cover your primula 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.