Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Snoqualmie you can figure out when it's a good idea to plant delphinium 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 moderate cold 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 Snoqualmie 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 grow to maturity. 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 when the weather gets warmer is on March 15 in Snoqualmie. It might get as low as 15°F during the coldest months of winter.

Since the USDA zone info for Snoqualmie is just an average the actual date of last frost changes from year to year. Half of the time in Snoqualmie it frosts late in the year after March 15 so make sure that you are prepared to protect your delphinium in the event of one of those late frosts.

USDA Zone Info for Snoqualmie

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Snoqualmie

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