Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when it's possible to plant salpiglossis is to refer to the USDA zone info for Mattoon.

Planting Calendar for Salpiglossis

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

Since salpiglossis are not cold tolerant it's necessary to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant salpiglossis in Mattoon 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. You probably don't want to wait any later than that or else 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

On average all chance of frost has passed is on April 15 in Mattoon. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Mattoon is just an average the actual date of last frost is different every year. Since half of the time in Mattoon last frost occurs after April 15 be ready to protect your salpiglossis in the event of a late frost.

USDA Zone Info for Mattoon

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Mattoon

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