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

It's a good idea to figure out when it's a good idea to plant salpiglossis by using the USDA zone info for Zone 4b.

Planting Calendar for Salpiglossis

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

Salpiglossis require warm weather which means that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant salpiglossis in Zone 4b 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 salpiglossis and expect a good harvest is probably August. You probably don't want to wait any later than that or else your salpiglossis may not have a chance to fully mature. Starting your salpiglossis indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4b. In the coldest months of winter you can expect an average low temperature of -25°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 4b and it can change quite a bit from year to year. Half of the time in Zone 4b it frosts late in the year after May 15 so always be ready to protect your salpiglossis in the event of one of those late frosts.

USDA Zone Info for Zone 4b

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Zone 4b

You may be interested in your other planting guides for Zone 4b.