When can I plant Begonias in Zone 4b

The USDA Zone info is a great tool for gardeners to help us determine 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 begonias in Zone 4b can be determined by looking at the USDA zone info.


Planting Calendar for Begonias

Frost tolerance for begonias: Not tolerant of frost.
When you should plant them: After the last frost.

Since begonias do not do well in cold weather you really should wait until after the last frost before you can plant them.

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

The earliest that you can plant begonias in Zone 4b 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 begonias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your begonias may not have a chance to fully mature. If you are starting your begonias indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Zone 4b. In the coldest months of winter we can expect an average low temperature of -25°F.

Always keep in mind that our actual date of last frost is an average because it is based on the USDA zone info for Zone 4b and it can change quite a bit from year to year. Since half of the time in Zone 4b there is a last frost after May 15 be ready to protect your begonias if we have a late frost.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-25°F
Highest Expected Low-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

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