One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to figure out when it's possible to plant astilbe by reviewing the USDA zone info for Holtville.

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 tend to make it in very little cold which means that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant astilbe in Holtville 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. You probably don't want to wait any later than that or else your astilbe may not have a chance to fully mature. If you are starting your astilbe indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on January 31 in Holtville. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Holtville may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Holtville it frosts late in the year after January 31 so be sure to be ready to protect your astilbe if you have one of those late frosts.

USDA Zone Info for Holtville

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 Holtville

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