One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

By checking out the USDA zone info for Watertown you will be able to figure out when you can plant onions.

Planting Calendar for Onions

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

Since onions are very cold tolerant you can plant them earlier in the year than more sensitive plants.

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

The last month that you can plant onions and expect a good harvest is probably August. Any later than that and your onions may not have a chance to grow to maturity. Starting your onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Watertown. You should expect an average low temperature of -25°F in the coldest months of winter.

It's important to remember that USDA zone info for Watertown is an average and the actual date of last frost changes from year to year. Since half of the time in Watertown there is a last frost after May 15 be ready to protect your onions in the event of a late frost.

USDA Zone Info for Watertown

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Watertown

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