The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Zone 4b you can determine when you can plant trachelium by using the USDA zone info.

Planting Calendar for Trachelium

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

Since trachelium are not cold tolerant you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant trachelium in Zone 4b is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant trachelium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your trachelium may not have a chance to grow to maturity. If you are starting your trachelium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4b. It might get as low as -25°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Zone 4b is an average and the actual date of last frost will vary from year to year. Since half of the time in Zone 4b you get a frost after May 15 be ready to protect your trachelium 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.