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

The earliest that you can plant regal geranium in Diamond Bar should be estimated by referring to the USDA zone info.

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.

You can plant regal geranium slightly earlier in the year because they are barely cold tolerant.

The earliest that you can plant regal geranium in Diamond Bar 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. You probably don't want to wait any later than that or else your regal geranium may not have a chance to really do well. If you are starting your regal geranium indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Diamond Bar is not always accurate and the actual date of last frost changes from year to year. Half of the time in Diamond Bar it frosts late in the year after January 31 so be sure to be ready to protect your regal geranium in the event of one of those late frosts.

USDA Zone Info for Diamond Bar

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 Diamond Bar

You may be interested in your other planting guides for Diamond Bar.