One of the best tools that you have as gardeners to help us determine 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 arabis in Umatilla can be determined by checking out the USDA zone info.

Planting Calendar for Arabis

Frost tolerance for arabis:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since arabis are very cold tolerant you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant arabis in Umatilla is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant arabis and expect a good harvest is probably September. If you wait any later than that and your arabis may not have a chance to fully mature. You can get started a few weeks earlier by starting your arabis indoors.

Last Frost Date

The average date of last frost is April 15 in Umatilla. In the coldest months of winter you should expect an average low temperature of 5°F.

Since the USDA zone info for Umatilla may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Umatilla you get a frost after April 15 so make sure that you are prepared to protect your arabis if you have a 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.