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.

A way of getting a good idea when to plant hypericum is to look at the USDA zone info for Rock Springs.

Planting Calendar for Hypericum

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

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

The earliest that you can plant hypericum 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 hypericum and expect a good harvest is probably August. Any later than that and your hypericum may not have a chance to grow to maturity. Starting your hypericum indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Remember that USDA zone info for Rock Springs is just 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 you get surprised by a frost after April 15 so be sure to be ready to cover your hypericum if you have one of those late frosts.

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.