When to Plant Delphinium in Colorado Springs, CO

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 consult the USDA zone info for Colorado Springs.


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 start planting them slightly earlier than more sensitive plants.

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 Colorado Springs 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 April 15 in Colorado Springs. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Colorado Springs is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Colorado Springs you get a frost after April 15 so make sure that you are prepared to cover your delphinium in the event of one of those late frosts.

USDA Zone Info for Colorado Springs

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°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 -10°F.

Plants to Grow in Colorado Springs

You may be interested in your other planting guides for Colorado Springs.