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

The best time to plant marigold in Riverdale can be estimated by reviewing the USDA zone info.

Planting Calendar for Marigold

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

Since marigold do not do well in cold weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant marigold in Riverdale 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. If you wait 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

In Riverdale the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

It's important to remember that USDA zone info for Riverdale may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Riverdale you get surprised by a frost after April 15 be ready to protect your marigold if you have one of those late frosts.

USDA Zone Info for Riverdale

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 Riverdale

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