One of the best tools that you have as gardeners to help us estimate 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.

One way of figuring out when to plant onions is to use the USDA zone info for Westminster.

Planting Calendar for Onions

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

Onions do ok in cold weather which means that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant onions in Westminster 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. If you wait any later than that and your onions may not have a chance to really do well. 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

In Westminster the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of 0°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Westminster and it is different every year. Half of the time in Westminster you get a frost after April 15 so make sure that you are ready to cover your onions if you have a late frost.

USDA Zone Info for Westminster

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Westminster

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