The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to estimate when it's the best time to plant rock cress by using the USDA zone info for Columbia.

Planting Calendar for Rock Cress

Frost tolerance for rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Rock Cress are one of those plants that can tolerate quite a bit of cold weather which means that you can get them planted much earlier than other frost tender plants.

The earliest that you can plant rock cress in Columbia 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 rock cress and expect a good harvest is probably September. Any later than that and your rock cress may not have a chance to fully mature. Starting your rock cress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on March 15 in Columbia. You can expect an average low temperature of 10°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Columbia and it is different every year. Since half of the time in Columbia there is a last frost after March 15 be ready to cover your rock cress if you have a surprise late frost.

USDA Zone Info for Columbia

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 Columbia

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