One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant marigold in Ann Arbor can be estimated by looking at the USDA zone info.

Planting Calendar for Marigold

Frost tolerance for marigold:	Not tolerant of frost.
When to plant:	After the last frost has passed.

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

The earliest that you can plant marigold in Ann Arbor 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 marigold and expect a good harvest is probably August. You probably don't want to wait any later than that or else your marigold may not have a chance to fully mature. Starting your marigold indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ann Arbor. It might get as low as -10°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Ann Arbor and it changes from year to year. Half of the time in Ann Arbor it frosts late in the year after April 15 so make sure that you are prepared to cover your marigold in the event of a late frost.

USDA Zone Info for Ann Arbor

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ann Arbor

You may be interested in your other planting guides for Ann Arbor.