Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when you can plant hypericum by referring to the USDA zone info for Winterset.

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 a bit earlier in the year than other frost tender plants.

The earliest that you can plant hypericum in Winterset 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 really do well. 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 Winterset. You should expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Winterset may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Winterset there is a last frost after April 15 so make sure that you are prepared to cover your hypericum if you have one of those late frosts.

USDA Zone Info for Winterset

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 Winterset

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