One of the first steps you take when you are determining your gardening schedule is find your 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.

The first chance to plant lisianthus in Zone 1b should be figured out by referring to the USDA zone info.

Planting Calendar for Lisianthus

Frost tolerance for lisianthus:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Lisianthus are not cold tolerant which means that you have to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant lisianthus 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 lisianthus and expect a good harvest is probably July. If you wait any later than that and your lisianthus may not have a chance to fully mature. Starting your lisianthus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is June 15 in Zone 1b. You can expect an average low temperature of -55°F in the coldest months of winter.

Remember that USDA zone info for Zone 1b may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 1b there is a last frost after June 15 so always be ready to cover your lisianthus in the event of a surprise 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.