Before planting it is a good idea to find your USDA Zone info to figure out 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.

By using the USDA zone info for Cairo you should be able to determine when it's a good idea to plant blue throatwort.

Planting Calendar for Blue Throatwort

Frost tolerance for blue throatwort:	Not tolerant of frost.
When to plant:	After the last frost.

Since blue throatwort require warm weather you have to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant blue throatwort in Cairo is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant blue throatwort and expect a good harvest is probably August. You probably don't want to wait any later than that or else your blue throatwort may not have a chance to really do well. If you are starting your blue throatwort indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Cairo. You should expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for Cairo is an average and the actual date of last frost changes from year to year. Since half of the time in Cairo last frost occurs after March 15 be ready to cover your blue throatwort 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.