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.

The first opportunity to plant tree onions in Port Isabel can be estimated by using 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 are one of those plants that can tolerate a tiny bit of cold weather which means that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant tree onions in Port Isabel 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 tree onions and expect a good harvest is probably September. Any later than that and your tree onions may not have a chance to grow to maturity. Starting your tree onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Port Isabel. You should expect an average low temperature of 30°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Port Isabel is an average and the actual date of last frost changes from year to year. Half of the time in Port Isabel you get surprised by a frost after January 31 so always be ready to protect your tree onions if you have a late frost.

USDA Zone Info for Port Isabel

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Port Isabel

You may be interested in your other planting guides for Port Isabel.