One of the first steps you take when you are estimating 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.

In Presidio you can estimate when to plant blue throatwort by using 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.

Blue Throatwort are not cold tolerant which tells us that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant blue throatwort in Presidio 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. Starting your blue throatwort indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Presidio. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Presidio is not always accurate the actual date of last frost will vary from year to year. Half of the time in Presidio it frosts late in the year after February 15 so make sure that you are ready to cover your blue throatwort in the event of one of those late frosts.

USDA Zone Info for Presidio

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 Presidio

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