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.

In Rock Falls you can determine when it's the best time to plant alternaria by reviewing the USDA zone info.

Planting Calendar for Alternaria

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

Since alternaria are not cold tolerant it is important to wait until after the last frost has passed before you can plant them.

The earliest that you can plant alternaria in Rock Falls 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. Any later than that and your alternaria may not have a chance to really do well. If you are starting your alternaria indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Rock Falls. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Rock Falls is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Rock Falls it frosts late in the year after April 15 so make sure that you are ready to cover your alternaria in the event of one of those late frosts.

USDA Zone Info for Rock Falls

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Rock Falls

You may be interested in your other planting guides for Rock Falls.