One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant sweet williams in Tomball can be figured out by checking out the USDA zone info.

Planting Calendar for Sweet Williams

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

Since sweet williams do well in moderate cold you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant sweet williams 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 sweet williams and expect a good harvest is probably October. Any later than that and your sweet williams may not have a chance to really do well. Starting your sweet williams indoors is a great way to get them started a couple of 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 may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Tomball there is a last frost after February 15 so make sure that you are prepared to protect your sweet williams 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.