Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when it's the best time to plant onions is to check out the USDA zone info for Hamilton.

Planting Calendar for Onions

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

Onions are very cold tolerant which means that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant onions in Hamilton 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 fully mature. Starting your onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Hamilton. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Hamilton and it can change quite a bit from year to year. Half of the time in Hamilton you get surprised by a frost after April 15 so make sure that you are prepared to cover your onions if you have a surprise late frost.

USDA Zone Info for Hamilton

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Hamilton

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