Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when it's possible to plant calendula is to check out the USDA zone info for Romeoville.

Planting Calendar for Calendula

Frost tolerance for calendula:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Calendula do well in a little bit of cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant calendula in Romeoville is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant calendula and expect a good harvest is probably September. If you wait any later than that and your calendula may not have a chance to really do well. If you are starting your calendula indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Romeoville. You should expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Romeoville and it is different every year. Since half of the time in Romeoville last frost occurs after April 15 be ready to cover your calendula if you have a surprise late frost.

USDA Zone Info for Romeoville

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Romeoville

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