One of the first steps you take when you are estimating 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.

You will be able to figure out when it's possible to plant salpiglossis by looking at the USDA zone info for Petersburg.

Planting Calendar for Salpiglossis

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

You really shouldn't plant salpiglossis until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant salpiglossis in Petersburg 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. If you wait any later than that and your salpiglossis may not have a chance to grow to maturity. Starting your salpiglossis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Petersburg. You should expect an average low temperature of 5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Petersburg is not always accurate and the actual date of last frost changes from year to year. Half of the time in Petersburg there is a last frost after April 15 so be sure to be ready to protect your salpiglossis in the event of one of those late frosts.

USDA Zone Info for Petersburg

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Petersburg

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