When to Plant Delphinium in Zone 1b

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when you can plant delphinium by reviewing the USDA zone info for Zone 1b.


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 get them planted just a bit earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant delphinium
Possibly ok, but a risky time to plant delphinium
Probably not a good time to plant delphinium

The earliest that you can plant delphinium in Zone 1b is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant delphinium and expect a good harvest is probably July. You probably don't want to wait any later than that or else your delphinium may not have a chance to grow to maturity. You can get started a little bit earlier by starting your delphinium indoors.

Last Frost Date

In Zone 1b the average date of last frost happens on June 15. It might get as low as -55°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 1b and it can change quite a bit from year to year. Since half of the time in Zone 1b you get surprised by a frost after June 15 be ready to cover your delphinium in the event of one of those late frosts.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)June 15
Average Date of First Frost (fall)July 15
Lowest Expected Low-55°F
Highest Expected Low-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.