One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of making a decision about when you can plant hypericum is to refer to the USDA zone info for Vernal.

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 are barely cold tolerant which tells us that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant hypericum in Vernal 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. If you wait any later than that and your hypericum may not have a chance to fully mature. If you are starting your hypericum 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 Vernal. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Vernal is an average the actual date of last frost changes from year to year. Half of the time in Vernal last frost occurs after April 15 so make sure that you are ready to cover your hypericum in the event of one of those late frosts.

USDA Zone Info for Vernal

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Vernal

You may be interested in your other planting guides for Vernal.