One of the best tools that you have as gardeners to help us figure out 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 Romulus should be used to estimate 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.

It's probably not a good idea to plant marigold until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant marigold in Romulus 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. Any later than that and your marigold may not have a chance to fully mature. You can get started a little bit earlier by starting your marigold indoors.

Last Frost Date

The average date of last frost is April 15 in Romulus. In the coldest months of winter you should expect an average low temperature of -10°F.

Always keep in mind that USDA zone info for Romulus is not always accurate and the actual date of last frost is different every year. Since half of the time in Romulus it frosts late in the year after April 15 be ready to protect your marigold in the event of a late frost.

USDA Zone Info for Romulus

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 Romulus

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