The USDA Zone info is a great tool for gardeners to help us determine 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.

In Sunnyvale you can figure out when to plant flower-of-an-hour by using 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.

Since flower-of-an-hour do ok in moderate cold you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant flower-of-an-hour in Sunnyvale 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. Starting your flower-of-an-hour indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Sunnyvale. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Sunnyvale may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Sunnyvale there is a last frost after March 15 so always be ready to protect your flower-of-an-hour if you have a surprise late frost.

USDA Zone Info for Sunnyvale

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Sunnyvale

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