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.

By using the USDA zone info for Gresham you should be able to estimate when to plant alternaria.

Planting Calendar for Alternaria

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

Alternaria are not cold tolerant which means that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant alternaria in Gresham 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 fully mature. 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 March 15 in Gresham. You can expect an average low temperature of 15°F in the coldest months of winter.

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 Gresham and it will vary from year to year. Since half of the time in Gresham you get surprised by a frost after March 15 be ready to protect your alternaria in the event of one of those late frosts.

USDA Zone Info for Gresham

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Gresham

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