One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

A way of figuring out when it's possible to plant delphinium is to consult the USDA zone info for Marshall.

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 means that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant delphinium in Marshall 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. You probably don't want to wait any later than that or else your delphinium may not have a chance to fully mature. Starting your delphinium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Marshall may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Marshall there is a last frost after March 15 so always be ready to protect your delphinium in the event of a surprise late frost.

USDA Zone Info for Marshall

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 Marshall

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