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.

The first opportunity to plant cosmos in Umatilla should be determined by reviewing the USDA zone info.

Planting Calendar for Cosmos

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

Cosmos are barely cold tolerant which means that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant cosmos 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 cosmos and expect a good harvest is probably August. Any later than that and your cosmos may not have a chance to grow to maturity. Starting your cosmos indoors is a great way to get them started a few weeks earlier.

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 can change quite a bit from year to year. Since half of the time in Umatilla it frosts late in the year after April 15 be ready to protect your cosmos 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.