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.

The best time to plant onions in Hilton Head Island can be figured out by reviewing the USDA zone info.

Planting Calendar for Onions

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

You can plant onions earlier in the year because they are very cold tolerant.

The earliest that you can plant onions in Hilton Head Island 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 onions and expect a good harvest is probably September. You probably don't want to wait any later than that or else your onions may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Hilton Head Island. In the coldest months of winter you should expect an average low temperature of 15°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Hilton Head Island and it changes from year to year. Since half of the time in Hilton Head Island you get surprised by a frost after March 15 be ready to protect your onions in the event of a surprise late frost.

USDA Zone Info for Hilton Head Island

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 Hilton Head Island

You may be interested in your other planting guides for Hilton Head Island.