Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of determining when it's a good idea to plant pennisetum is to examine the USDA zone info for Rock Springs.

Planting Calendar for Pennisetum

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

Pennisetum are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant pennisetum in Rock Springs 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 pennisetum and expect a good harvest is probably August. Any later than that and your pennisetum may not have a chance to really do well. If you are starting your pennisetum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Rock Springs is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Rock Springs it frosts late in the year after April 15 so always be ready to protect your pennisetum if you have a late frost.

USDA Zone Info for Rock Springs

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 Rock Springs

You may be interested in your other planting guides for Rock Springs.