The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of making a decision about when it's the best time to plant marigold is to use the USDA zone info for Zionsville.

Planting Calendar for Marigold

Frost tolerance for marigold:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

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

The earliest that you can plant marigold in Zionsville 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. Starting your marigold indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

It's important 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 Zionsville and it will vary from year to year. Half of the time in Zionsville you get surprised by a frost after April 15 so always be ready to cover your marigold if you have a late frost.

USDA Zone Info for Zionsville

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 Zionsville

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