When to Plant Marigold in Zone 3b

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

One way of estimating when it's a good idea to plant marigold is to use the USDA zone info for Zone 3b.


Planting Calendar for Marigold

Frost tolerance for marigold: Not tolerant of frost.
When to plant: After the last frost when the weather gets warmer.

Since marigold require warm weather you must wait until after the last frost when the weather gets warmer before you can plant them.

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

The earliest that you can plant marigold in Zone 3b 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 marigold and expect a good harvest is probably August. Any later than that and your marigold may not have a chance to fully mature. Starting your marigold indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on May 15 in Zone 3b. You should expect an average low temperature of -35°F in the coldest months of winter.

Since the USDA zone info for Zone 3b is an average the actual date of last frost will vary from year to year. Half of the time in Zone 3b you get surprised by a frost after May 15 so make sure that you are prepared to cover your marigold if you have a surprise late frost.

USDA Zone Info for Zone 3b

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)September 15
Lowest Expected Low-35°F
Highest Expected Low-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Zone 3b

You may be interested in your other planting guides for Zone 3b.