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.

The first opportunity to plant alternaria in Harrisburg can be determined by looking at the USDA zone info.

Planting Calendar for Alternaria

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

It's probably not a good idea to plant alternaria until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant alternaria in Harrisburg 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 alternaria and expect a good harvest is probably August. You probably don't want to wait any later than that or else your alternaria may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your alternaria indoors.

Last Frost Date

On average the last frost is on April 15 in Harrisburg. It might get as low as -5°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Harrisburg is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Harrisburg you get a frost after April 15 be ready to protect your alternaria in the event of a surprise late frost.

USDA Zone Info for Harrisburg

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Harrisburg

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