The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of determining when you can plant alternaria is to refer to the USDA zone info for Colby.

Planting Calendar for Alternaria

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

It's not a good idea to plant alternaria until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant alternaria in Colby 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. You can get started a few weeks earlier by starting your alternaria indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Colby and it changes from year to year. Since half of the time in Colby it frosts late in the year after April 15 be ready to cover your alternaria if you have a surprise late frost.

USDA Zone Info for Colby

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 Colby

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