One of the first steps you take when you are figuring out 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.

In Joshua you can estimate when it's a good idea to plant astilbe by using the USDA zone info.

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 means that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant astilbe in Joshua is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant astilbe and expect a good harvest is probably August. Any later than that and your astilbe may not have a chance to really do well. If you are starting your astilbe indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on March 15 in Joshua. In the coldest months of winter you should expect an average low temperature of 10°F.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Joshua and it changes from year to year. Half of the time in Joshua last frost occurs after March 15 so just be sure to be ready to cover your astilbe if you have a surprise late frost.

USDA Zone Info for Joshua

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Joshua

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