Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's possible to plant nierembergia is to check out the USDA zone info for Umatilla.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since nierembergia require warm weather you need to wait until after all chance of frost has passed before you can plant them.

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

Last Frost Date

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

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Umatilla and it can change quite a bit from year to year. Half of the time in Umatilla you get surprised by a frost after April 15 so always be ready to cover your nierembergia 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.