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.

You can estimate when it's a good idea to plant oxalis in Houston by using the USDA zone info.

Planting Calendar for Oxalis

Frost tolerance for oxalis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's not a good idea to plant oxalis until after the last frost because they require warm weather.

The earliest that you can plant oxalis 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 oxalis and expect a good harvest is probably September. If you wait any later than that and your oxalis may not have a chance to grow to maturity. If you are starting your oxalis indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is 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 is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Houston you get surprised by a frost after February 15 be ready to cover your oxalis 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.