Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In San Antonio you can determine when it's possible to plant canna by looking at the USDA zone info.

Planting Calendar for Canna

Frost tolerance for canna:	Not tolerant of frost.
When to plant:	After the last frost.

Since canna do not do well in cold weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant canna in San Antonio is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant canna and expect a good harvest is probably August. You probably don't want to wait any later than that or else your canna may not have a chance to grow to maturity. If you are starting your canna 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 March 15 in San Antonio. You can expect an average low temperature of 15°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Antonio and it can change quite a bit from year to year. Since half of the time in San Antonio you get surprised by a frost after March 15 be ready to cover your canna if you have a surprise late frost.

USDA Zone Info for San Antonio

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in San Antonio

You may be interested in your other planting guides for San Antonio.