One of the best tools that you have as gardeners to help us estimate 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.

It's possible to determine when it's possible to plant oenothera by using the USDA zone info for Tomball.

Planting Calendar for Oenothera

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

Since oenothera do well in moderate cold you can plant them a little earlier in the year than other frost tender plants.

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

It's important to remember that USDA zone info for Tomball is an average and the actual date of last frost will vary from year to year. Since half of the time in Tomball there is a last frost after February 15 be ready to cover your oenothera in the event of 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.