The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Zone 4b you will be able to determine when you can plant tritoma.

Planting Calendar for Tritoma

Frost tolerance for tritoma:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Tritoma are very cold tolerant which tells us that you can start planting them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant tritoma in Zone 4b 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 tritoma and expect a good harvest is probably August. If you wait any later than that and your tritoma may not have a chance to fully mature. Starting your tritoma indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Zone 4b the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 4b and it can change quite a bit from year to year. Half of the time in Zone 4b last frost occurs after May 15 so be sure to be ready to cover your tritoma if you have one of those late frosts.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.