One of the first steps you take when you are determining your gardening schedule is find your 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 will be able to estimate when it's a good idea to plant violas by using the USDA zone info for Tomball.

Planting Calendar for Violas

Frost tolerance for violas:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Violas are one of those plants that can tolerate quite a bit of cold weather which tells us that you can get them planted much earlier than plants that are more sensitive to the cold.

The earliest that you can plant violas in Tomball is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant violas and expect a good harvest is probably October. You probably don't want to wait any later than that or else your violas may not have a chance to really do well. You can get started a little bit earlier by starting your violas indoors.

Last Frost Date

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

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Tomball and it is different every year. Half of the time in Tomball you get surprised by a frost after February 15 so make sure that you are prepared to protect your violas 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.