One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

In Cairo you can determine when it's a good idea to plant tree onions by looking at the USDA zone info.

Planting Calendar for Tree onions

Frost tolerance for tree onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Tree onions can survive in a tiny bit of cold which means that you can plant them slightly earlier in the year than more sensitive plants.

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

The last month that you can plant tree onions and expect a good harvest is probably August. If you wait any later than that and your tree onions may not have a chance to fully mature. You can get started a few weeks earlier by starting your tree onions indoors.

Last Frost Date

The average date of last frost is March 15 in Cairo. It might get as low as 15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Cairo is not always accurate and the actual date of last frost will vary 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 tree onions 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.