Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Gypsum you can determine when it's the best time to plant delphinium by using 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 tend to make it in a tiny bit of cold which tells us that you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant delphinium in Gypsum 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 little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Gypsum. In the coldest months of winter you can expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Gypsum is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Gypsum there is a last frost after April 15 so just be sure to be ready to cover your delphinium if you have one of those late frosts.

USDA Zone Info for Gypsum

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Gypsum

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