One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant onions in Highland can be estimated by looking at 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 much earlier in the year because they do well in cold.

The earliest that you can plant onions in Highland is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably October. If you wait any later than that and your onions may not have a chance to grow to maturity. If you are starting your onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Highland. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Highland is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Highland you get surprised by a frost after February 15 so just be sure to be ready to cover your onions if you have one of those late frosts.

USDA Zone Info for Highland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Highland

You may be interested in your other planting guides for Highland.