The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Raritan you can figure out when it's possible to plant penstemon by checking out the USDA zone info.

Planting Calendar for Penstemon

Frost tolerance for penstemon:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Penstemon tend to make it in a little bit of cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

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

The last month that you can plant penstemon and expect a good harvest is probably September. You probably don't want to wait any later than that or else your penstemon may not have a chance to grow to maturity. If you are starting your penstemon 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 Raritan. In the coldest months of winter you should expect an average low temperature of -5°F.

It's important to remember that USDA zone info for Raritan is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Raritan it frosts late in the year after April 15 be ready to cover your penstemon 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.