One of the best tools that you have as gardeners to help us estimate 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 use the USDA zone info for Duluth.

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 tend to make it in some cold which means that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant hypericum in Duluth 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. You can get started a couple of weeks earlier by starting your hypericum indoors.

Last Frost Date

The average date of last frost is April 15 in Duluth. You can expect an average low temperature of 5°F in the coldest months of winter.

Always keep in mind that USDA zone info for Duluth is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Duluth you get a frost after April 15 be ready to protect your hypericum if you have one of those late frosts.

USDA Zone Info for Duluth

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Duluth

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