One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's the best time to plant iresene in Umatilla 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.

Since iresene are not cold tolerant you must wait until after the last frost before you can plant them.

The earliest that you can plant iresene in Umatilla 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. Any later than that and your iresene may not have a chance to fully mature. If you are starting your iresene indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Umatilla the average date of last frost happens on April 15. You should expect an average low temperature of 5°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Umatilla and it is different every year. Half of the time in Umatilla there is a last frost after April 15 so always be ready to protect your iresene if you have one of those late frosts.

USDA Zone Info for Umatilla

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Umatilla

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