One of the best tools that you have as gardeners to help us figure out 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.

A way of getting a good idea when it's possible to plant primula is to refer to the USDA zone info for Scottsdale.

Planting Calendar for Primula

Frost tolerance for primula:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Primula are very cold tolerant which means that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant primula in Scottsdale is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant primula and expect a good harvest is probably October. You probably don't want to wait any later than that or else your primula may not have a chance to fully mature. Starting your primula indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Scottsdale the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

It's important to remember that USDA zone info for Scottsdale is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Scottsdale you get surprised by a frost after February 15 so be sure to be ready to cover your primula in the event of 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.