One of the first steps you take when you are estimating 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 reffered to in order to determine when it's a good idea to plant hibiscus.

Planting Calendar for Hibiscus

Frost tolerance for hibiscus:	Not tolerant of frost.
When to plant:	After the last frost.

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

The earliest that you can plant hibiscus 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 hibiscus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your hibiscus may not have a chance to fully mature. If you are starting your hibiscus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Casper the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

Remember that USDA zone info for Casper may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Casper you get surprised by a frost after April 15 so make sure that you are ready to cover your hibiscus if you have a surprise 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.