The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. 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 Wooster should be reffered to in order to estimate when it's a good idea 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.

Delphinium do ok in mild cold which means that you can plant them slightly earlier in the year than other frost tender plants.

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

Last Frost Date

In Wooster the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Wooster and it can change quite a bit from year to year. Since half of the time in Wooster there is a last frost after April 15 be ready to protect your delphinium if you have a late frost.

USDA Zone Info for Wooster

Here is the info for USDA Zone 6a.

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

Plants to Grow in Wooster

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