One of the best tools that you have as gardeners to help us figure out 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 Raritan should be reviewed to estimate when it's the best time to plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant dahlias until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant dahlias in Raritan is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant dahlias and expect a good harvest is probably August. Any later than that and your dahlias may not have a chance to grow to maturity. Starting your dahlias indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Raritan is not always accurate the actual date of last frost will vary from year to year. Half of the time in Raritan you get a frost after April 15 so always be ready to protect your dahlias in the event of a late frost.

USDA Zone Info for Raritan

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 Raritan

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