One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

You can determine when it's possible to plant blue throatwort in Signal Hill by checking out the USDA zone info.

Planting Calendar for Blue Throatwort

Frost tolerance for blue throatwort:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since blue throatwort require warm weather it is necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant blue throatwort in Signal Hill 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. Any later than that and your blue throatwort may not have a chance to grow to maturity. Starting your blue throatwort indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Signal Hill. It might get as low as 35°F during the coldest months of winter.

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 Signal Hill and it can change quite a bit from year to year. Since half of the time in Signal Hill there is a last frost after January 31 be ready to cover your blue throatwort in the event of a surprise late frost.

USDA Zone Info for Signal Hill

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Signal Hill

You may be interested in your other planting guides for Signal Hill.