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.

You will be able to figure out when it's possible to plant four-o-clock flower by referring to the USDA zone info for Umatilla.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since four-o-clock flower require warm weather you have to wait until after the last frost has passed before you can plant them.

The earliest that you can plant four-o-clock flower 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 four-o-clock flower and expect a good harvest is probably August. Any later than that and your four-o-clock flower may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

The average date of last frost is April 15 in Umatilla. It might get as low as 5°F during the coldest months of winter.

It's important to remember that USDA zone info for Umatilla is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Umatilla you get a frost after April 15 be ready to cover your four-o-clock flower 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.