The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of estimating when it's a good idea to plant primula is to use the USDA zone info for Casa Grande.

Planting Calendar for Primula

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

You can plant primula earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

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

The last month that you can plant primula and expect a good harvest is probably September. You probably don't want to wait any later than that or else your primula may not have a chance to grow to maturity. Starting your primula indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Casa Grande. In the coldest months of winter you should expect an average low temperature of 5°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Casa Grande and it can change quite a bit from year to year. Half of the time in Casa Grande it frosts late in the year after April 15 so make sure that you are ready to protect your primula in the event of one of those late frosts.

USDA Zone Info for Casa Grande

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Casa Grande

You may be interested in your other planting guides for Casa Grande.