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

By checking out the USDA zone info for Alamo you should be able to figure out when it's a good idea to plant delphinium.

Planting Calendar for Delphinium

Frost tolerance for delphinium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since delphinium do ok in moderate cold you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

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

The last month that you can plant delphinium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your delphinium may not have a chance to grow to maturity. Starting your delphinium indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Alamo the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

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

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.