One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when it's the best time to plant oxalis is to check out the USDA zone info for Tomball.

Planting Calendar for Oxalis

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

You should not plant oxalis until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant oxalis in Tomball 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 really do well. Starting your oxalis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Tomball. You should expect an average low temperature of 20°F in the coldest months of winter.

Remember that USDA zone info for Tomball is an average and the actual date of last frost will vary from year to year. Half of the time in Tomball you get a frost after February 15 so just be sure to be ready to cover your oxalis in the event of a surprise late frost.

USDA Zone Info for Tomball

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 Tomball

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