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 chance to plant alternaria in Walla Walla should be determined by checking out the USDA zone info.

Planting Calendar for Alternaria

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

You can not plant alternaria until after the last frost because they do not do well in cold weather.

The earliest that you can plant alternaria in Walla Walla 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 grow to maturity. You can get started a couple of weeks earlier by starting your alternaria indoors.

Last Frost Date

In Walla Walla the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Walla Walla is an average the actual date of last frost changes from year to year. Since half of the time in Walla Walla you get surprised by a frost after April 15 be ready to cover your alternaria in the event of a surprise late frost.

USDA Zone Info for Walla Walla

Here is the info for USDA Zone 7a.

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

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Walla Walla

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