The USDA Zone info is a great tool for gardeners to help us estimate 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.

The USDA zone info for Wheaton should 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 the last frost.

Since marigold are not cold tolerant you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant marigold in Wheaton 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 really do well. You can get started a couple of weeks earlier by starting your marigold indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Wheaton. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Wheaton is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Wheaton it frosts late in the year after April 15 be ready to cover your marigold in the event of one of those late frosts.

USDA Zone Info for Wheaton

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 Wheaton

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