One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Sunnyvale you can estimate when it's a good idea to plant bidens by looking at the USDA zone info.

Planting Calendar for Bidens

Frost tolerance for bidens:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably a bad idea to plant bidens until after the last frost because they require warm weather.

The earliest that you can plant bidens 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 bidens and expect a good harvest is probably September. If you wait any later than that and your bidens may not have a chance to grow to maturity. If you are starting your bidens indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Sunnyvale the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Remember that USDA zone info for Sunnyvale may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Sunnyvale it frosts late in the year after February 15 so always be ready to protect your bidens in the event of a late frost.

USDA Zone Info for Sunnyvale

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Sunnyvale

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