One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Alma can be reffered to in order to estimate when it's possible to plant delphinium.

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 a bit earlier in the year than other frost tender plants.

The earliest that you can plant delphinium in Alma 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 really do well. 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 Alma. It might get as low as 5°F during the coldest months of winter.

Since the USDA zone info for Alma is an average the actual date of last frost changes from year to year. Half of the time in Alma you get a frost after April 15 so always be ready to protect your delphinium in the event of a surprise late frost.

USDA Zone Info for Alma

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Alma

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