One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

You can determine when it's a good idea to plant xerianthemum in Rock Springs by referring to the USDA zone info.

Planting Calendar for Xerianthemum

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

Xerianthemum do well in some cold which means that you can plant them a bit earlier in the year than more sensitive plants.

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

Last Frost Date

On average the last frost is on April 15 in Rock Springs. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Rock Springs is just an average the actual date of last frost is different every year. Since half of the time in Rock Springs you get surprised by a frost after April 15 be ready to cover your xerianthemum if you have a surprise 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.