One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant dianthus in Umatilla can be determined by using the USDA zone info.

Planting Calendar for Dianthus

Frost tolerance for dianthus:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Dianthus tend to make it in some cold which tells us that you can plant them a little earlier in the year than other frost tender plants.

The earliest that you can plant dianthus 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 dianthus and expect a good harvest is probably September. You probably don't want to wait any later than that or else your dianthus may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your dianthus indoors.

Last Frost Date

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

Since the USDA zone info for Umatilla is just an average the actual date of last frost is different every year. Since half of the time in Umatilla there is a last frost after April 15 be ready to cover your dianthus if you have 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.