One of the best tools that you have as gardeners to help us figure out 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 Ripon you can determine when to plant petunias by checking out 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 do ok in a tiny bit of cold which means that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant petunias in Ripon 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 grow to maturity. 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 the last frost has passed is on April 15 in Ripon. In the coldest months of winter you can expect an average low temperature of -20°F.

Just be sure to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ripon and it is different every year. Since half of the time in Ripon you get a frost after April 15 be ready to protect your petunias in the event of one of those late frosts.

USDA Zone Info for Ripon

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Ripon

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