One of the best tools that you have as gardeners to help us determine 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 determining when it's a good idea to plant hypericum is to examine the USDA zone info for Zone 1b.

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.

Since hypericum do ok in moderate cold you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant hypericum in Zone 1b is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant hypericum and expect a good harvest is probably July. Any later than that and your hypericum may not have a chance to grow to maturity. If you are starting your hypericum 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 June 15 in Zone 1b. It might get as low as -55°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 1b is not always accurate and the actual date of last frost is different every year. Since half of the time in Zone 1b it frosts late in the year after June 15 be ready to cover your hypericum if you have a late frost.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-55°F
Highest Expected Low	-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.