Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Zone 4a you can figure out when you can plant trachelium by looking at the USDA zone info.

Planting Calendar for Trachelium

Frost tolerance for trachelium:	Not tolerant of frost.
When to plant:	After the last frost.

Trachelium require warm weather which means that it is important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant trachelium in Zone 4a 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 really do well. Starting your trachelium indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Zone 4a the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 4a and it will vary from year to year. Half of the time in Zone 4a you get a frost after May 15 so always be ready to protect your trachelium if you have a late frost.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

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