One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Scottsdale you will be able to determine when it's a good idea to plant sunflowers.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Sunflowers require warm weather which tells us that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant sunflowers 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 sunflowers and expect a good harvest is probably September. If you wait any later than that and your sunflowers may not have a chance to really do well. If you are starting your sunflowers indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Scottsdale and it can change quite a bit from year to year. Half of the time in Scottsdale you get a frost after February 15 so make sure that you are ready to protect your sunflowers if you have a 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.