One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Dayton can be looked at to figure out when it's possible to plant marigold.

Planting Calendar for Marigold

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

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

The earliest that you can plant marigold in Dayton 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 marigold and expect a good harvest is probably September. Any later than that and your marigold may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your marigold indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Dayton. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Dayton is an average the actual date of last frost will vary from year to year. Since half of the time in Dayton last frost occurs after February 15 be ready to cover your marigold in the event of one of those late frosts.

USDA Zone Info for Dayton

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

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

Plants to Grow in Dayton

You may be interested in your other planting guides for Dayton.