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.

In Madison you can estimate when to plant petunias by referring to the USDA zone info.

Planting Calendar for Petunias

Frost tolerance for petunias:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Petunias tend to make it in very little cold which means that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant petunias in Madison 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 petunias and expect a good harvest is probably August. If you wait any later than that and your petunias may not have a chance to fully mature. If you are starting your petunias indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed 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 an average the actual date of last frost will vary from year to year. Since half of the time in Madison last frost occurs after March 15 be ready to protect your petunias if you have a late frost.

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.