One of the first steps you take when you are estimating 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.

You can estimate when it's possible to plant flower-of-an-hour in Washington by reviewing the USDA zone info.

Planting Calendar for Flower-of-an-Hour

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

Flower-of-an-Hour can survive in mild cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant flower-of-an-hour in Washington 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 flower-of-an-hour and expect a good harvest is probably August. Any later than that and your flower-of-an-hour may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your flower-of-an-hour indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Washington. You should expect an average low temperature of -5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Washington is an average and the actual date of last frost will vary from year to year. Half of the time in Washington last frost occurs after April 15 so make sure that you are ready to cover your flower-of-an-hour if you have a late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Washington

You may be interested in your other planting guides for Washington.