Before planting it is a good idea to find your USDA Zone info to determine 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.

A common way of making a decision about when it's the best time to plant sunflowers is to use the USDA zone info for Alamo.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant sunflowers until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant sunflowers in Alamo 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 sunflowers and expect a good harvest is probably September. Any later than that and your sunflowers may not have a chance to really do well. Starting your sunflowers indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost has passed is on February 15 in Alamo. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Alamo is not always accurate the actual date of last frost changes from year to year. Half of the time in Alamo last frost occurs after February 15 so make sure that you are ready to cover your sunflowers in the event of a late frost.

USDA Zone Info for Alamo

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Alamo

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