One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

It's possible to figure out when it's a good idea to plant astilbe by checking out the USDA zone info for Santa Clara.

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 barely cold tolerant which tells us that you can plant them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant astilbe in Santa Clara 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. Any later than that and your astilbe may not have a chance to fully mature. Starting your astilbe indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Santa Clara the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Santa Clara and it will vary from year to year. Half of the time in Santa Clara there is a last frost after February 15 so just be sure to be ready to cover your astilbe if you have a surprise late frost.

USDA Zone Info for Santa Clara

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 Santa Clara

You may be interested in your other planting guides for Santa Clara.