One of the first steps you take when you are getting a good idea 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 common way of making a decision about when to plant delphinium is to examine the USDA zone info for Bethlehem.

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 a tiny bit of cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant delphinium in Bethlehem 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. You can get started a couple of weeks earlier by starting your delphinium indoors.

Last Frost Date

In Bethlehem the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -5°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Bethlehem and it is different every year. Since half of the time in Bethlehem you get a frost after April 15 be ready to protect your delphinium if you have a surprise late frost.

USDA Zone Info for Bethlehem

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 Bethlehem

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