The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when it's a good idea to plant astilbe by reviewing the USDA zone info for Los Altos.

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.

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

The earliest that you can plant astilbe in Los Altos 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. Starting your astilbe indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Los Altos may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Los Altos you get surprised by a frost after February 15 so make sure that you are prepared to protect your astilbe in the event of a late frost.

USDA Zone Info for Los Altos

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 Los Altos

You may be interested in your other planting guides for Los Altos.