One of the first steps you take when you are determining 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.

The USDA zone info for Houston can be reffered to in order to figure out when to plant alyssum.

Planting Calendar for Alyssum

Frost tolerance for alyssum:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant alyssum earlier in the year because they do well in cold.

The earliest that you can plant alyssum in 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 alyssum and expect a good harvest is probably October. Any later than that and your alyssum may not have a chance to grow to maturity. You can get started a little bit earlier by starting your alyssum indoors.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Houston and it changes from year to year. Since half of the time in Houston there is a last frost after February 15 be ready to protect your alyssum if you have a late frost.

USDA Zone Info for 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 Houston

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