One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of figuring out when it's a good idea to plant salpiglossis is to examine the USDA zone info for Princeton.

Planting Calendar for Salpiglossis

Frost tolerance for salpiglossis:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's probably a bad idea to plant salpiglossis until after the last frost because they require warm weather.

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

The last month that you can plant salpiglossis and expect a good harvest is probably August. Any later than that and your salpiglossis may not have a chance to fully mature. If you are starting your salpiglossis indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Princeton. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Princeton is an average the actual date of last frost changes from year to year. Half of the time in Princeton you get surprised by a frost after April 15 so be sure to be ready to protect your salpiglossis in the event of a late frost.

USDA Zone Info for Princeton

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 Princeton

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