One of the best tools that you have as gardeners to help us estimate 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 USDA zone info for Mount Vernon can be reffered to in order to estimate when you can 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.

Delphinium do well in mild cold which tells us that you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant delphinium in Mount Vernon 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 little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Mount Vernon. You can expect an average low temperature of -5°F in the coldest months of winter.

Remember that USDA zone info for Mount Vernon may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Mount Vernon last frost occurs after April 15 so be sure to be ready to cover your delphinium in the event of a surprise late frost.

USDA Zone Info for Mount Vernon

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Mount Vernon

You may be interested in your other planting guides for Mount Vernon.