Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when to plant bidens is to refer to the USDA zone info for Scottsdale.

Planting Calendar for Bidens

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

Bidens are not cold tolerant which tells us that it is necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant bidens in Scottsdale 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. Starting your bidens indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Scottsdale. You should expect an average low temperature of 25°F in the coldest months of winter.

Keep in mind that USDA zone info for Scottsdale is just an average and the actual date of last frost changes from year to year. Since half of the time in Scottsdale you get surprised by a frost after February 15 be ready to cover your bidens in the event of a surprise late frost.

USDA Zone Info for Scottsdale

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 Scottsdale

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