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.

It's possible to determine when it's possible to plant delphinium by looking at the USDA zone info for Kenai.

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 are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant delphinium in Kenai is April. However, you really should wait until May 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 grow to maturity. You can get started a little bit earlier by starting your delphinium indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in Kenai. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Kenai is not always accurate the actual date of last frost changes from year to year. Half of the time in Kenai there is a last frost after May 15 so make sure that you are prepared to protect your delphinium in the event of a late frost.

USDA Zone Info for Kenai

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Kenai

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