One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Southlake it's a good idea to determine when it's the best time 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.

You can plant delphinium just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant delphinium in Southlake 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 few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Southlake. In the coldest months of winter you should expect an average low temperature of 10°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Southlake and it changes from year to year. Half of the time in Southlake it frosts late in the year after March 15 so be sure to be ready to protect your delphinium if you have a surprise late frost.

USDA Zone Info for Southlake

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Southlake

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