Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Port Isabel it's a good idea to determine when it's the best time to plant welsh onion.

Planting Calendar for Welsh onion

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

Since welsh onion do ok in moderate cold you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant welsh onion 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 welsh onion and expect a good harvest is probably September. If you wait any later than that and your welsh onion may not have a chance to really do well. If you are starting your welsh onion indoors then you might be able to get away with starting them 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.

Since the USDA zone info for Port Isabel is an average the actual date of last frost is different every year. Since half of the time in Port Isabel you get surprised by a frost after January 31 be ready to protect your welsh onion in the event of 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.