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.

In Altoona you can figure out when to plant calliopsis by checking out the USDA zone info.

Planting Calendar for Calliopsis

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

Since calliopsis are not cold tolerant you really should wait until after the last frost has passed before you can plant them.

The earliest that you can plant calliopsis in Altoona 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 calliopsis and expect a good harvest is probably August. You probably don't want to wait any later than that or else your calliopsis may not have a chance to really do well. If you are starting your calliopsis indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Altoona. You can expect an average low temperature of -10°F in the coldest months of winter.

Remember that USDA zone info for Altoona may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Altoona there is a last frost after April 15 so be sure to be ready to cover your calliopsis if you have a surprise late frost.

USDA Zone Info for Altoona

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 Altoona

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