Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Calistoga you should be able to figure out when it's the best time to plant blue throatwort.

Planting Calendar for Blue Throatwort

Frost tolerance for blue throatwort:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You should not plant blue throatwort until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant blue throatwort in Calistoga 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 blue throatwort and expect a good harvest is probably September. Any later than that and your blue throatwort may not have a chance to fully mature. Starting your blue throatwort 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 Calistoga. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Calistoga is just an average the actual date of last frost changes from year to year. Half of the time in Calistoga it frosts late in the year after February 15 so make sure that you are prepared to protect your blue throatwort in the event of a late frost.

USDA Zone Info for Calistoga

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Calistoga

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