The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of estimating when to plant delphinium is to check out the USDA zone info for Catasauqua.

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.

You can plant delphinium slightly earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

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

Last Frost Date

The average date of last frost is April 15 in Catasauqua. In the coldest months of winter you can expect an average low temperature of -5°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Catasauqua and it will vary from year to year. Half of the time in Catasauqua it frosts late in the year after April 15 so make sure that you are prepared to cover your delphinium in the event of a surprise late frost.

USDA Zone Info for Catasauqua

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°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 0°F.

Plants to Grow in Catasauqua

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