One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. 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 Casper should be reviewed to estimate when it's a good idea to plant trifolium.

Planting Calendar for Trifolium

Frost tolerance for trifolium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Trifolium do ok in mild cold which means that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant trifolium in Casper is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant trifolium and expect a good harvest is probably August. If you wait any later than that and your trifolium may not have a chance to really do well. Starting your trifolium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Casper may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Casper last frost occurs after April 15 so just be sure to be ready to protect your trifolium in the event of a late frost.

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.