One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when it's the best time to plant astilbe is to examine the USDA zone info for Philomath.

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 do ok in moderate cold which means that you can plant them slightly earlier than plants that are more sensitive to the cold.

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

Last Frost Date

In Philomath the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that USDA zone info for Philomath is an average and the actual date of last frost changes from year to year. Half of the time in Philomath last frost occurs after March 15 so make sure that you are prepared to cover your astilbe in the event of one of those late frosts.

USDA Zone Info for Philomath

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Philomath

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