The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to figure out when to plant flower-of-an-hour by checking out the USDA zone info for Seattle.

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.

You can plant flower-of-an-hour slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant flower-of-an-hour in Seattle 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. If you wait any later than that and your flower-of-an-hour may not have a chance to grow to maturity. If you are starting your flower-of-an-hour indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Seattle the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Since the USDA zone info for Seattle is not always accurate the actual date of last frost is different every year. Half of the time in Seattle you get surprised by a frost after March 15 so make sure that you are prepared to cover your flower-of-an-hour if you have one of those late frosts.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Seattle

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