The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. 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 Tomball should be used to estimate when to plant impatiens.

Planting Calendar for Impatiens

Frost tolerance for impatiens:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant impatiens until after the last frost because they do not do well in cold weather.

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

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Tomball. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Tomball is an average the actual date of last frost changes from year to year. Half of the time in Tomball there is a last frost after February 15 so just be sure to be ready to cover your impatiens 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.