One of the best tools that you have as gardeners to help us figure out 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.

The USDA zone info for Houston can be reffered to in order to estimate when it's possible to plant saxifraga.

Planting Calendar for Saxifraga

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

Saxifraga do ok in moderate cold which tells us that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant saxifraga 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 saxifraga and expect a good harvest is probably September. If you wait any later than that and your saxifraga may not have a chance to really do well. You can get started a few weeks earlier by starting your saxifraga indoors.

Last Frost Date

In Houston the average date of last frost happens on February 15. It might get as low as 20°F during the coldest months of winter.

It's important to remember 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 Houston and it is different every year. Half of the time in Houston there is a last frost after February 15 so just be sure to be ready to protect your saxifraga 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.