Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when you can plant diascia in Zone 4b by checking out the USDA zone info.

Planting Calendar for Diascia

Frost tolerance for diascia:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant diascia a little bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant diascia 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 diascia and expect a good harvest is probably August. If you wait any later than that and your diascia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your diascia indoors.

Last Frost Date

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

Since the USDA zone info for Zone 4b is just an average the actual date of last frost is different every year. Half of the time in Zone 4b there is a last frost after May 15 so be sure to be ready to cover your diascia 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.