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.

By using the USDA zone info for Houston you will be able to figure out when to plant celosia.

Planting Calendar for Celosia

Frost tolerance for celosia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since celosia require warm weather you need to wait until after the last frost has passed before you can plant them.

The earliest that you can plant celosia in Houston is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant celosia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your celosia may not have a chance to fully mature. If you are starting your celosia 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 Houston. In the coldest months of winter you should expect an average low temperature of 20°F.

Since the USDA zone info for Houston may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Houston it frosts late in the year after February 15 be ready to protect your celosia if you have a surprise 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.