When to Plant Delphinium in Zone 8a

One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

A way of estimating when it's a good idea to plant delphinium is to refer to the USDA zone info for Zone 8a.


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.

You can plant delphinium a bit earlier in the year because they do ok in moderate 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 8a 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. If you wait any later than that and your delphinium may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your delphinium indoors.

Last Frost Date

The average date of last frost is March 15 in Zone 8a. In the coldest months of winter you can expect an average low temperature of 10°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Zone 8a and it can change quite a bit from year to year. Half of the time in Zone 8a it frosts late in the year after March 15 so make sure that you are ready to cover your delphinium in the event of one of those late frosts.

USDA Zone Info for Zone 8a

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low10°F
Highest Expected Low15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Zone 8a

You may be interested in your other planting guides for Zone 8a.