One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant marigold in Collinsville should be figured out by using 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 require warm weather it is important to wait until after the last frost before you can plant them.

The earliest that you can plant marigold in Collinsville 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. You can get started a few weeks earlier by starting your marigold indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Collinsville. You should expect an average low temperature of 0°F in the coldest months of winter.

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

USDA Zone Info for Collinsville

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Collinsville

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