One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant petunias in Harvard can be figured out by reviewing 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 are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant petunias in Harvard 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 really do well. 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

In Harvard the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that USDA zone info for Harvard is not always accurate and the actual date of last frost is different every year. Half of the time in Harvard it frosts late in the year after April 15 so make sure that you are prepared to cover your petunias in the event of a surprise late frost.

USDA Zone Info for Harvard

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 Harvard

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