One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

By using the USDA zone info for San Bernardino it's a good idea to estimate when 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.

It's probably a bad idea to plant blue throatwort until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant blue throatwort in San Bernardino 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 grow to maturity. You can get started a couple of weeks earlier by starting your blue throatwort indoors.

Last Frost Date

The average date of last frost is February 15 in San Bernardino. You can expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for San Bernardino is just an average the actual date of last frost changes from year to year. Since half of the time in San Bernardino there is a last frost after February 15 be ready to protect your blue throatwort if you have one of those late frosts.

USDA Zone Info for San Bernardino

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 San Bernardino

You may be interested in your other planting guides for San Bernardino.