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

In Casper you can estimate when it's the best time to plant marigold by reviewing the USDA zone info.

Planting Calendar for Marigold

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

You can not plant marigold until after the last frost because they require warm weather.

The earliest that you can plant marigold in Casper 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. If you are starting your marigold indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Casper. You can expect an average low temperature of -20°F in the coldest months of winter.

Always keep in mind that USDA zone info for Casper is just an average and the actual date of last frost changes from year to year. Since half of the time in Casper it frosts late in the year after April 15 be ready to cover your marigold if you have one of those late frosts.

USDA Zone Info for Casper

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Casper

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