Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Princeton it's a good idea to determine when it's a good idea to plant torenia.

Planting Calendar for Torenia

Frost tolerance for torenia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since torenia are not cold tolerant it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant torenia in Princeton is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant torenia and expect a good harvest is probably August. Any later than that and your torenia may not have a chance to grow to maturity. Starting your torenia indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Princeton the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

Since the USDA zone info for Princeton is just an average the actual date of last frost will vary from year to year. Since half of the time in Princeton it frosts late in the year after May 15 be ready to cover your torenia if you have a surprise late frost.

USDA Zone Info for Princeton

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Princeton

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