The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Umatilla you can estimate when it's possible to plant tomatos by checking out the USDA zone info.

Planting Calendar for Tomatos

Frost tolerance for tomatos:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant tomatos until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant tomatos 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 tomatos and expect a good harvest is probably August. If you wait any later than that and your tomatos may not have a chance to fully mature. If you are starting your tomatos indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Umatilla. You can expect an average low temperature of 5°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Umatilla and it changes from year to year. Half of the time in Umatilla there is a last frost after April 15 so make sure that you are prepared to protect your tomatos in the event of a surprise late frost.

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.