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.

The best time to plant bells of ireland in Houston should be estimated by looking at the USDA zone info.

Planting Calendar for Bells of Ireland

Frost tolerance for bells of ireland:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bells of Ireland do ok in moderate cold which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant bells of ireland in Houston 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 bells of ireland and expect a good harvest is probably September. If you wait any later than that and your bells of ireland may not have a chance to grow to maturity. Starting your bells of ireland indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Houston may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Houston there is a last frost after February 15 be ready to protect your bells of ireland in the event of 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.