One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Zone 4b it's a good idea to determine when to plant plectranthus.

Planting Calendar for Plectranthus

Frost tolerance for plectranthus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant plectranthus until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant plectranthus 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 plectranthus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your plectranthus may not have a chance to really do well. You can get started a little bit earlier by starting your plectranthus indoors.

Last Frost Date

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

Since the USDA zone info for Zone 4b is not always accurate the actual date of last frost changes from year to year. Half of the time in Zone 4b you get a frost after May 15 so make sure that you are prepared to cover your plectranthus if you have a late frost.

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.