Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for South Houston you should be able to estimate when it's a good idea to plant sweet williams.

Planting Calendar for Sweet Williams

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

Sweet Williams do well in moderate cold which tells us that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant sweet williams in South Houston 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 grow to maturity. Starting your sweet williams indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for South Houston is just an average the actual date of last frost is different every year. Since half of the time in South Houston last frost occurs after February 15 be ready to protect your sweet williams if you have a late frost.

USDA Zone Info for South Houston

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 South Houston

You may be interested in your other planting guides for South Houston.