One of the best tools that you have as gardeners to help us determine 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 first chance to plant delphinium in Mendham should be figured out by looking at the USDA zone info.

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 are one of those plants that can tolerate a tiny bit of cold weather you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant delphinium in Mendham 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. Any later than that and your delphinium may not have a chance to grow to maturity. If you are starting your delphinium indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Mendham and it changes from year to year. Since half of the time in Mendham it frosts late in the year after April 15 be ready to protect your delphinium in the event of a surprise late frost.

USDA Zone Info for Mendham

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 Mendham

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