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

The best time to plant onions in Madison can be determined by checking out 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 a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant onions in Madison 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. Any later than that and your onions may not have a chance to really do well. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Madison. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for Madison is just an average the actual date of last frost will vary from year to year. Half of the time in Madison you get surprised by a frost after March 15 so make sure that you are ready to protect your onions in the event of one of those late frosts.

USDA Zone Info for Madison

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Madison

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