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

The USDA zone info for Irvine can be read to determine when it's possible to plant regal geranium.

Planting Calendar for Regal Geranium

Frost tolerance for regal geranium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Regal Geranium are barely cold tolerant which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant regal geranium in Irvine 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 regal geranium and expect a good harvest is probably September. If you wait any later than that and your regal geranium may not have a chance to really do well. Starting your regal geranium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Irvine the average date of last frost happens on January 31. You should expect an average low temperature of 30°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Irvine and it is different every year. Half of the time in Irvine it frosts late in the year after January 31 so always be ready to cover your regal geranium in the event of one of those late frosts.

USDA Zone Info for Irvine

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Irvine

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