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.

A common way of making a decision about when it's the best time to plant astilbe is to consult the USDA zone info for Pasadena.

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 are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant astilbe in Pasadena 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 grow to maturity. You can get started a couple of weeks earlier by starting your astilbe indoors.

Last Frost Date

In Pasadena the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Pasadena is an average the actual date of last frost changes from year to year. Since half of the time in Pasadena last frost occurs after January 31 be ready to cover your astilbe in the event of one of those late frosts.

USDA Zone Info for Pasadena

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 Pasadena

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