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.

By checking out the USDA zone info for Grinnell it's possible to determine when you can plant salpiglossis.

Planting Calendar for Salpiglossis

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

You should not plant salpiglossis until after the last frost when the weather gets warmer because they require warm weather.

The earliest that you can plant salpiglossis in Grinnell 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 little bit earlier.

Last Frost Date

In Grinnell the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -20°F.

Always keep in mind that USDA zone info for Grinnell is an average and the actual date of last frost will vary from year to year. Half of the time in Grinnell last frost occurs after April 15 so make sure that you are ready to protect your salpiglossis in the event of a surprise late frost.

USDA Zone Info for Grinnell

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Grinnell

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