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.

The USDA zone info for Roanoke can be looked at to determine when it's a good idea to plant diascia.

Planting Calendar for Diascia

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

Diascia do ok in mild cold which means that you can plant them just a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant diascia in Roanoke is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant diascia and expect a good harvest is probably September. Any later than that and your diascia may not have a chance to really do well. You can get started a few weeks earlier by starting your diascia indoors.

Last Frost Date

The average date of last frost is April 15 in Roanoke. You can expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Roanoke is just an average the actual date of last frost will vary from year to year. Half of the time in Roanoke there is a last frost after April 15 so be sure to be ready to protect your diascia in the event of a late frost.

USDA Zone Info for Roanoke

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Roanoke

You may be interested in your other planting guides for Roanoke.