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

The USDA zone info for Umatilla can be looked at to figure out when it's possible to plant gomphrena.

Planting Calendar for Gomphrena

Frost tolerance for gomphrena:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Gomphrena tend to make it in mild cold which tells us that you can plant them just a tiny bit earlier in the year than more sensitive plants.

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

The last month that you can plant gomphrena and expect a good harvest is probably August. You probably don't want to wait any later than that or else your gomphrena may not have a chance to really do well. You can get started a couple of weeks earlier by starting your gomphrena indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Umatilla. You should 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 may not be accurate from year to year because it is based on the USDA zone info for Umatilla and it can change quite a bit from year to year. Since half of the time in Umatilla there is a last frost after April 15 be ready to protect your gomphrena in the event of 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.