The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for San Bruno it's a good idea 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 the last frost.

It's probably a bad idea to plant blue throatwort until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant blue throatwort in San Bruno 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 blue throatwort and expect a good harvest is probably September. If you wait any later than that and your blue throatwort may not have a chance to really do well. If you are starting your blue throatwort indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is January 31 in San Bruno. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for San Bruno may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in San Bruno you get surprised by a frost after January 31 be ready to protect your blue throatwort in the event of a late frost.

USDA Zone Info for San Bruno

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 San Bruno

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