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

The USDA zone info for Colton can be read to figure out when you can plant blue throatwort.

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.

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

The earliest that you can plant blue throatwort in Colton 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 really do well. You can get started a little bit earlier by starting your blue throatwort indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Colton. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Colton is just an average the actual date of last frost will vary from year to year. Since half of the time in Colton last frost occurs after February 15 be ready to protect your blue throatwort in the event of a late frost.

USDA Zone Info for Colton

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 Colton

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