One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when it's a good idea to plant onions by looking at the USDA zone info for Grantsville.

Planting Calendar for Onions

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

Onions do well in cold which means that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant onions in Grantsville 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 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

The average date of last frost is April 15 in Grantsville. You can expect an average low temperature of 0°F in the coldest months of winter.

It's important 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 Grantsville and it can change quite a bit from year to year. Since half of the time in Grantsville last frost occurs after April 15 be ready to protect your onions if you have a surprise late frost.

USDA Zone Info for Grantsville

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 Grantsville

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