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.

It's a good idea to determine when it's the best time to plant blue throatwort by looking at the USDA zone info for Houston.

Planting Calendar for Blue Throatwort

Frost tolerance for blue throatwort:	Not tolerant of frost.
When to plant:	After the last frost has passed.

You can not 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 Houston 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. You probably don't want to wait any later than that or else your blue throatwort may not have a chance to really do well. Starting your blue throatwort indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for Houston may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Houston it frosts late in the year after February 15 so always be ready to protect your blue throatwort if you have a surprise late frost.

USDA Zone Info for Houston

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 Houston

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