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.

In Roma you can estimate when to plant marigold by checking out the USDA zone info.

Planting Calendar for Marigold

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

It's not a good idea to plant marigold until after the last frost because they are not cold tolerant.

The earliest that you can plant marigold in Roma 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

The average date of last frost is February 15 in Roma. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Roma is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Roma there is a last frost after February 15 be ready to protect your marigold if you have a late frost.

USDA Zone Info for Roma

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Roma

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