One of the best tools that you have as gardeners to help us figure out 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.

You can estimate when you can plant delphinium in Austin by referring to the USDA zone info.

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.

Delphinium do ok in moderate cold which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant delphinium in Austin 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 delphinium and expect a good harvest is probably August. Any later than that and your delphinium may not have a chance to really do well. If you are starting your delphinium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Austin. In the coldest months of winter you should expect an average low temperature of 15°F.

Since the USDA zone info for Austin is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Austin it frosts late in the year after March 15 be ready to cover your delphinium in the event of a surprise late frost.

USDA Zone Info for Austin

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 Austin

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