One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Colton should be used to estimate when you can plant astilbe.

Planting Calendar for Astilbe

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

Astilbe do ok in moderate cold which means that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant astilbe in Colton 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 astilbe and expect a good harvest is probably September. If you wait any later than that and your astilbe may not have a chance to really do well. You can get started a little bit earlier by starting your astilbe indoors.

Last Frost Date

On average all chance of frost has passed is on February 15 in Colton. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Colton is an average the actual date of last frost will vary from year to year. Half of the time in Colton you get surprised by a frost after February 15 so be sure to be ready to protect your astilbe if you have a late frost.

USDA Zone Info for Colton

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 Colton

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