The USDA Zone info is a great tool for gardeners to help us estimate 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.

By referring to the USDA zone info for Cairo you should be able to determine when you can plant rock cress.

Planting Calendar for Rock Cress

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

You can plant rock cress a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant rock cress in Cairo 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. If you wait any later than that and your rock cress may not have a chance to grow to maturity. If you are starting your rock cress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Cairo is just an average the actual date of last frost changes from year to year. Half of the time in Cairo there is a last frost after March 15 so just be sure to be ready to cover your rock cress in the event of one of those late frosts.

USDA Zone Info for Cairo

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Cairo

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