One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant iresene in Tualatin can be determined by using the USDA zone info.

Planting Calendar for Iresene

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

It's not a good idea to plant iresene until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant iresene in Tualatin 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 iresene and expect a good harvest is probably August. You probably don't want to wait any later than that or else your iresene may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your iresene indoors.

Last Frost Date

On average the last frost is on March 15 in Tualatin. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Tualatin is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Tualatin it frosts late in the year after March 15 so always be ready to cover your iresene in the event of one of those late frosts.

USDA Zone Info for Tualatin

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 Tualatin

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