When can I plant Impatiens in Zone 4a

One of the first steps we take when we are estimating 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.

By checking out the USDA zone info for Zone 4a you will be able to figure out when it's possible to plant impatiens.


Planting Calendar for Impatiens

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

Impatiens are not cold tolerant which tells us that it is necessary 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 impatiens
Possibly ok, but a risky time to plant impatiens
Probably not a good time to plant impatiens

The earliest that you can plant impatiens in Zone 4a 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 impatiens and expect a good harvest is probably August. You probably don't want to wait any later than that or else your impatiens may not have a chance to really do well. You can get started a couple of weeks earlier by starting your impatiens indoors.

Last Frost Date

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

Remember that our actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Zone 4a and it changes from year to year. Since half of the time in Zone 4a last frost occurs after May 15 be ready to protect your impatiens if we have one of those late frosts.

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.