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

One way of estimating when to plant delphinium is to check out the USDA zone info for South Burlington.

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 other plants that might not handle the cold.

The earliest that you can plant delphinium in South Burlington 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. 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 is on April 15 in South Burlington. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for South Burlington is just an average the actual date of last frost will vary from year to year. Since half of the time in South Burlington there is a last frost after April 15 be ready to cover your delphinium in the event of a late frost.

USDA Zone Info for South Burlington

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in South Burlington

You may be interested in your other planting guides for South Burlington.