One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Rockwall you should be able to determine when it's possible to plant columbine.

Planting Calendar for Columbine

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

Columbine are moderately cold tolerant which tells us that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant columbine in Rockwall 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 columbine and expect a good harvest is probably September. If you wait any later than that and your columbine may not have a chance to fully mature. You can get started a few weeks earlier by starting your columbine indoors.

Last Frost Date

The average date of last frost is March 15 in Rockwall. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Rockwall is just an average the actual date of last frost will vary from year to year. Half of the time in Rockwall there is a last frost after March 15 so always be ready to cover your columbine if you have a surprise late frost.

USDA Zone Info for Rockwall

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Rockwall

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