One of the first steps you take when you are figuring out 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.

A common way of estimating when to plant petunias is to consult the USDA zone info for Lake Forest.

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 do well in some cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant petunias in Lake Forest 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. Any later than that and your petunias may not have a chance to fully mature. Starting your petunias indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Lake Forest. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Lake Forest is just an average and the actual date of last frost will vary from year to year. Since half of the time in Lake Forest it frosts late in the year after April 15 be ready to protect your petunias in the event of a surprise late frost.

USDA Zone Info for Lake Forest

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Lake Forest

You may be interested in your other planting guides for Lake Forest.