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.

It's a good idea to estimate when to plant regal geranium by checking out the USDA zone info for Colusa.

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.

Since regal geranium do ok in moderate cold you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant regal geranium in Colusa 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. Any later than that and your regal geranium may not have a chance to fully mature. You can get started a few weeks earlier by starting your regal geranium indoors.

Last Frost Date

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

Since the USDA zone info for Colusa is just an average the actual date of last frost will vary from year to year. Since half of the time in Colusa last frost occurs after February 15 be ready to cover your regal geranium if you have a surprise late frost.

USDA Zone Info for Colusa

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 Colusa

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