The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to determine when it's a good idea to plant columbine by looking at the USDA zone info for Gretna.

Planting Calendar for Columbine

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

Columbine are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant columbine in Gretna 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. Any later than that and your columbine may not have a chance to grow to maturity. Starting your columbine indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Gretna. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Gretna is an average the actual date of last frost will vary from year to year. Since half of the time in Gretna you get a frost after April 15 be ready to protect your columbine if you have one of those late frosts.

USDA Zone Info for Gretna

Here is the info for USDA Zone 5b.

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

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

Plants to Grow in Gretna

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