One of the first steps you take when you are getting a good idea 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.

In Tomball you can determine when it's the best time to plant diascia by checking out the USDA zone info.

Planting Calendar for Diascia

Frost tolerance for diascia:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Diascia tend to make it in some cold which means that you can plant them a little bit earlier in the year than more sensitive plants.

The earliest that you can plant diascia 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 diascia and expect a good harvest is probably October. If you wait any later than that and your diascia may not have a chance to grow to maturity. Starting your diascia indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Tomball. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Tomball is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Tomball you get surprised by a frost after February 15 be ready to cover your diascia if you have a 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.