One of the first steps you take when you are estimating 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 making a decision about when it's the best time to plant delphinium is to examine the USDA zone info for Indianola.

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.

Since delphinium do ok in moderate cold you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant delphinium in Indianola 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 grow to maturity. Starting your delphinium indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Indianola. In the coldest months of winter you should expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Indianola may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Indianola you get a frost after April 15 be ready to cover your delphinium in the event of one of those late frosts.

USDA Zone Info for Indianola

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 Indianola

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