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.

The best time to plant delphinium in Morton should be determined by looking at 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 some cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant delphinium in Morton 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. If you wait any later than that and your delphinium may not have a chance to really do well. Starting your delphinium indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Morton. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Morton is not always accurate the actual date of last frost changes from year to year. Half of the time in Morton you get surprised by a frost after April 15 so always be ready to cover your delphinium if you have a late frost.

USDA Zone Info for Morton

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Morton

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